The Mole. Chapter 10. Dimensional Analysis. The Mole. How much mass is in one atom of carbon12? Molar Mass of Atoms 3/1/2015


 Colleen Thompson
 2 years ago
 Views:
Transcription
1 The Mole Chapter 10 1 Objectives Use the mole and molar mass to make conversions among moles, mass, and number of particles Determine the percent composition of the components of a compound Calculate empirical and molecular formulas for compounds Determine the formulas for hydrates Examine relationship between volume and amount of gas (Avogadro s Law Ch. 13.2) 2 Dimensional Analysis Conversion Factors: What is 8a*5b/2a= 20 b  Real Example: 1 mile = 5280 ft Convert 5.5 miles to feet. 5.5 miles x 5280 ft = 1 mi ft 3 The Mole Mole (mol) measures the number of particles of a substance (atom, molecule, formula unit) Using mole is just a shorthand way for saying 6.02 x particles 6.02 x particles = Avogadro s number 4 How much mass is in one atom of carbon12? Molar Mass of Atoms Definition: g of Carbon12 is exactly 1 mol (6.02x10 23 ) of Carbon12 atoms. Therefore: Exactly 12 amu (by definition) 5 6 1
2 Finding Molar Mass of Other Elements All other elements are determined with respect to Carbon12 by mass spectroscopy. Finding Molar Mass of Other Elements Another element: Fe56 has amu So it is /12 or 4.67 x the mass of C12 If we put all the iron isotopes together, the average Fe atom is amu Each amu has a mass of 1.66 x g, so: For example: the He4 has 4/12 or 1/3 the mass of Carbon Finding the Molar Mass of an Element. x. = 9.27 x g/atom. x. = g/mol Fe Mass of Atoms If you have two 1 g samples of different substances, what do they have in common? 9 10 Mass of Atoms 11 The atomic mass of ONE iron atom is AMU (atomic mass units). The molar mass of (a mole of) iron is grams. 12 2
3 The number of grams in a mole is called the molar mass. Why does a mole of iron weigh more than a mole of carbon? For the same reason that a dozen bowling balls weighs more than a dozen golf balls! 13 Bowling balls are heavier than golf balls. 14 Mass of Iron on Balance g of iron (iron s molar mass) on scale is: 1 mole of iron (1 mol Fe = g Fe) 6.02 x atoms of iron A conversion you already know. How many eggs are in 14 dozen eggs? 14 dozen eggs x 12 eggs = 168 eggs 1 dozen eggs How many dozens of eggs would you need to buy if you were going to feed 504 people 1 egg each? 504 eggs x 1 dozen eggs = 42 dozen eggs 12 eggs Moles and Number of Particles Examples If have 2 mole of iron how many atoms of iron do you have? 2 moles Fe x 6.02x10 23 atoms = 12.04x10 23 atoms 1mole If have x atoms of iron how many moles of iron have you? 12.04x10 23 atoms x 1 mole = 2.0 moles 6.02x10 23 atoms Mass and Moles Examples What is the mass in grams of 2.00 moles of Cu? 2.00 moles Cu x 63.5 grams = 127 grams Cu 1mole Cu How moles is 190. g of Cu? 190. g Cu x 1 mole Cu = 3.00 mol Cu 63.5 g
4 Mass Particles Examples In order to go from mass to number of particles, you have to go through moles. How many atoms are in 46.0g of Na? 46.0 g x mol Na x Mass Particles Examples What is the mass in grams of x atoms of Al? x atoms x 2.50 mol Al x Mass (grams) Multiply by molar mass from periodic table Flowchart Divide by molar mass from periodic table Moles Divide by 6.02 X Multiply by 6.02 X Atoms or Molecules 21 Mass, Moles, and Number of Particles Practice How many moles are in 25.5 g of Ag? How many grams are mol of silicon (Si)? How many atoms are in 15.0 mol of Xe? How many moles are in 7.23 x atoms of Xe? How many atoms are in 6.50 g of B? How many grams are in 5.53 x atoms of Mg? 22 Practice Practice How many moles are in 25.5 g of Ag? How many grams are mol of silicon (Si)?
5 Practice How many atoms are in 15.0 mol of Xe? Practice How many moles are in 7.23 x atoms of Xe? Practice How many atoms are in 6.50 g of B? Practice How many grams are in 5.53 x atoms of Mg? One Mole of Four Elements OneMole Quantities of Some Elements & Compounds One mole each of helium, sulfur, copper, and mercury. How many atoms of helium are present? Of sulfur? Of copper? Of mercury?
6 We can also calculate the molar mass of compounds like carbon dioxide. The formula for carbon dioxide is CO 2. That means there is one carbon atom and two oxygen atoms in every molecule of CO We can also calculate the molar mass of compounds like carbon dioxide. Carbon weighs grams/mole Oxygen weighs grams/mole. Therefore CO 2 has a molar mass of: C + O + O = CO = g 32 Atom Ca Cl CaCl 2 Finding Molar Mass of CaCl 2 (assume 1 mole compound) # mol Atoms in 1 mol of compound Molar Mass (g/mol) Total (g) Let s find out the molar mass of glucose (C 6 H 12 O 6 ). Use the molar masses from the periodic table: Carbon 12.0 grams/mole Hydrogen 1.0 gram/mole Oxygen 16.0 grams/mole How many grams are in a mole of glucose (C 6 H 12 O 6 )? Carbon: 6 x 12.0 g/mol = 72.0 g Hydrogen: 12 x 1.0 g/mol =12.0 g Oxygen: 6 x 16.0 g/mol = 96.0 g g/mol (For consistency, round all molar masses (elements & compounds) to 0.1 g.) Moles to Mass of Compound How many grams of KCl are in 2.30 mol of KCl? First, find molar mass. K: 1 K x 39.1 g/mol = 39.1 g Cl: 1 Cl x 35.5 g/mol = 35.5 g 74.6 g/mol
7 Moles to Mass of Compound How many grams of KCl are in 2.30 mol of KCl? # of moles Molar mass 2.30 mol KCl x 74.6 g KCl = mol KCl =171.6 g KCl = 172 g KCl (proper Sig Figs) 37 Mass to Moles in a Compound How many moles of KCl are present in grams KCl? First, determine the molar mass of KCl. (Same as before, which is 74.6 g/mol) Then, divide mass by molar mass to get moles g KCl x 1 mol =3.40 mol KCl 74.6 g KCl 38 Mass to Moles in a Compound Can determine the number of moles of each of the atoms/ions that make up the compound. Multiply by ion/compound conversion factor. Mass to Moles in a Compound How many moles of Cl  ions are there 5.5 mol of CaCl 2? 5.5 mol CaCl 2 x 2 mol Cl  = 11.0 mol Cl  1 mol CaCl 2 Conversion factor: mole of specific atom 1 mol of compound Example: 2 mol Cl  1 mol CaCl Mass, Moles & Particles Use the flowchart from the elemental calculations and use them for compounds. Moles are still central Get to mass (g) by multiplying by molar mass Get to # molecules (covalent compounds) or formula units (ionic compounds) by multiplying by Avogadro s number. Mass to Moles in a Compound How many moles of Na + are there in g of Na 2 CO 3? First, find Molar Mass of Na 2 CO 3 : Na: 2 x 23.0 g/mol = 46.0 g C: 1 x 12.0 g/mol = 12.0 g O: 3 x 16.0 g/mol = 48.0 g Molar Mass = g/mol
8 Mass to Moles in a Compound How many moles of Na + are there in g of Na 2 CO 3? Next, find the number of moles of Na 2 CO g x 1 mol = mol Na 2 CO g Use conversion of moles of ion/mole of compound mol Na 2 CO 3 x 2 mol Na += 10.6 mol Na + Mass to Number of Particles How many Na + ions are in g of Na 2 CO 3? Note: Looking for individual # of ions. Will be a very large number. First, find # of moles of the ion or element you are interested in. In this case it was 10.6 mol Na +. 1 mol Na 2 CO Mass to Number of Particles Finally, multiply # of mol by Avogadro s Constant mol Na + x 6.02 x ions 1 mol = 6.38 x Na + ions Mass to Number of Particles How many formula units of Na 2 CO 3 are there in the 5.30 mol of Na 2 CO 3? 5.30 mol Na 2 CO 3 x 6.02 x Frm Unts 1 mol of Na 2 CO 3 = 31.9 x formula Units Determine the # of formula units, the number of moles of each ion, and the number of each ion in: a) 2.50 mol ZnCl 2 Determine the # of formula units in 2.50 mole of ZnCl 2. b) g of Fe 2 S 3 Determine the mass in grams of 2.11x10 24 formula units of Na 2 S
9 Determine the # of moles Zn 2+ ions in 2.50 mol of ZnCl 2. Determine the # of moles Cl  ions in 2.50 mol of ZnCl Determine the # of Zn 2+ ions in 2.50 mol of ZnCl 2. Determine the # of Cl  ions in 2.50 mol of ZnCl Determine the # of formula units in in 623.7g of Fe 2 S 3. Determine the # of formula units in in 623.7g of Fe 2 S
10 Determine the # of moles of Fe 3+ ions in 623.7g of Fe 2 S 3. Determine the # of moles of S 2 ions in 623.7g of Fe 2 S Determine the # Fe 3+ ions ions in 623.7g of Fe 2 S 3. Determine the # S 2 ions in 623.7g of Fe 2 S Determine the # Fe 3+ ions and S 2 ions in 623.7g of Fe 2 S 3. Determine the mass in grams of 2.11x10 24 formula units of Na 2 S. Hint: First find Molar Mass
11 Determine the mass in grams of 2.11x10 24 formula units of Na 2 S. Ch Percent Composition Percent composition is the percent, by mass, of each element in a compound. In general, it s the mass of the element/mass of the formula: Mass of element x 100 = %mass Mass of compound of element Percent Composition Example: If a 50.0 g sample of H 2 O contains 5.6 g of H and 44.4 g of O the percent composition is: 5.6 g H x 100% = 11.1% H 50.0 g H 2 O 44.5 g O x 100% = 88.9% O 50 g H 2 O Percent Composition You can calculate the percent composition by finding the mass of each element in 1 mole of a compound. Example: Water s formula is H 2 O which means there are 2 mol of hydrogen and 1 mol oxygen in one mol of water Percent Composition So, if you have 1 mol of water, you have 18.0 g of water (molar mass) The 18.0 g of water is made up of 2 mol Hydrogen (2 g) and 1 mol oxygen (16 g). H: 2 g x 100% = 11.1% 18.0 g O: 16 g x 100% = 88.9% 18 g 65 Percent Composition Example Calculate the percent composition of each element in Ca(OH) Determine the mass of each element present in 1 mol of cmpd. Ca: 1 mol x 40.1 g/mol = 40.1 g O: 2 mol x 16.0 g/mol = 32.0 g H: 2 mol x 1.0 g/mol = 2.0 g 2. Determine mass in g of one mole of compound g 66 11
12 Percent Composition Example (Continued) 3. Calculate percentage of each element Ca: 40.1 g/74.1 g * 100 = 54.1% H: 2.0 g/74.1 g * 100 = 2.7% O: 32.0 g/74.1 g * 100 = 43.2% Percent Composition Practice Determine the % Comp of each element in: 1. KBr 2. Fe 2 O 3 3. Barium nitrate Empirical Formulas An empirical formula for a compound is the formula of a substance written with the smallest integer subscripts. In other words, the simplest mole ratios. You can use the percent composition of a compound to determine is empirical formula. Empirical Formula Steps to determine formula: 1. Consider 100g of compound 2. Convert percentages of elements to grams 3. Divide each element s respective mass by its molar mass to obtain moles 4. Divide each mole value by the smallest mole value. This give the mole ratio. 5. Multiply by appropriate number to get whole number subscripts Empirical Formula Example Determining the Empirical Formula from the Masses of Elements. We have determined the mass percentage composition of calcium chloride: 36.0% Ca and 64.0% Cl. What is the empirical formula of calcium chloride? Empirical formula Calcium Chloride (36% Calcium; 64% Chlorine) Atom Mass % In grams Molar Mass Ca Cl Moles Ratio Ratio Ca : Cl Empirical Formula
13 Empirical Formula Practice Determine the empirical formula of a compound that is 36.8% nitrogen and 63.2% oxygen. More Empirical Formula Practice Determining The Empirical Formula from Percentage Composition. (General) Benzene is a widely used industrial solvent. This compound has been analyzed and found to contain 92.26% carbon and 7.74% hydrogen by mass. What is its empirical formula? Hint: Consider a 100 g sample. The empirical formula is: Molecular Formulas Compounds with different molecular formulas can have the same empirical formula, and such substances will have the same percentage composition. Remember that the molecular formula has the actual number of atoms of each element that make one molecule of that compound. Molecular Formula from Empirical Formula The molecular formula of a compound is a multiple of its empirical formula. Molecular mass = n x empirical formula mass where n = number of empirical formula units in the molecule. Eg. Compound A = C 2 H 2 Compound B = C 6 H 6 both have the empirical formula = Molecular Formula Example Determining the Molecular Formula from the Percent Composition and Molar Mass. We have already determined the mass composition and empirical formula of benzene (CH). In a separate experiment, the molar mass of benzene was determined to be What is the molecular formula of benzene Mass of empirical formula = Molar mass benzene _ = Mass of empirical formula 77 Molecular Formula Example What is the molecular formula of a compound that has an empirical formula of CH 3 and a molar mass of 30.0 g/mol. What is the mass of each empirical unit? C: 1 x 12.0 = 12.0 H: 3 x 1.0 = How many times units? 30/15 = 2 So molecular formula is C 2 H
14 Molecular Formula Practice 1. Empirical Formula is NO 2 ; molar mass is 92.0 g/mol 2. A compound contains 26.76% C, 2.21%H, 71.17% O and has a molar mass of g/mol. Determine its molecular formula. Ch Salt Hydrates Water molecules bound to a compound For example, CaCl 2 2H 2 O Each molecule of calcium chloride has two water molecules bound to it See conceptual picture next slide CaCl 2 2H 2 O Cl  Ca +2 Cl Water Water Example of Percent Composition of a Hydrate Determine the percent salt and percent water (by mass) in 1 mol of CaCl 2 2H 2 O. 1. Find the mass of 1 mole of the compound. Ca: 1 x 40.1 = 40.1 Cl: 2 x 35.5 = 71.0 = g/mol H 2 O: 2 x 18.0 = Example of Percent Composition of a Hydrate 2. Find the percent of salt g CaCl 2 = 75.5% CaCl g CaCl 2 2H 2 O 3. Find the percent of water g H 2 O = 24.5% H 2 O g CaCl 2 2H 2 O Or you can say 100% 75.5% CaCl 2 = 24.5% H 2 O. 83 Determination of Formula Example A nickel(ii) cyanide hydrate, Ni(CN) 2 XH 2 O, contains 39.4% water by mass. What is the formula of the hydrated compound? 1. Assume 100 g of the compound. If it is 39.4% water, it is or 60.6% Ni(CN) 2. So there are 60.6 g of Ni(CN)
15 Determination of Formula Example 2. Determine the number of moles of the salt and the water g Ni(CN) 2 = 0.547mol Ni(CN) g/mol Ni: 1 x 58.7 = 58.7 C: 2 x 12.0 = 24.0 N: 2 x 14.0 = g H 2 O = 2.19 mol H 2 O 18.0 g/mol Determination of Formula Example 3. Determine the mol ratio of the water to the salt mol H 2 O mol Ni(CN) 2 = 4 mol H 2 O/mol Ni(CN) 2 So the formula is Ni(CN) 2 4H 2 O Moles and Gases (Ch ) Remember Boyle s Law, Charles s Law and Combined Gas Law? Boyle: P 1 V 1 =P 2 V 2 Charles: V 1 /T 1 =V 2 /T 2 Combined: P 1 V 1 = P 2 V 2 T 1 T 2 There is another law that relates volume to moles. The Gas Laws Avogadro s Law Amedeo Avogadro ( ) studied the relationship between volume and amount of gas The Gas Laws Avogadro s Law Avogadro s Principle: Equal volumes of gas at the same P & T contain equal numbers of particles (molecules or atoms). Avogadro s Law The volume of a gas at constant P & T is directly proportional to the number of moles of gas. Volume α n; hold P & T constant V = k x n 89 Avogadro s Principle As an extension of Avogadro s Principle, 1 mol of a gas at 0 C (273 K) and 1 atm of pressure occupies a volume of 22.4 Liters (Molar Volume) 0 C (273 K) and 1 atm of pressure are standard temperature and pressure (STP) 90 15
16 Avogadro s Principle Since volume is related to moles, if you know the volume a gas occupies at STP, you know the # of moles L 1 mol Example: If you have 11.2 L of a gas at STP, how many moles are there? 11.2 L x 1 mol = mole 22.4 L Avogadro s Principle Practice Given the conditions at STP find: Volume of mol of gas # of moles of N 2 (g) in a 2.0 L flask # of atoms of Kr in 28.5 L Ch Ideal Gas Law The gas laws that we covered all have one thing in common: they relate the volume of the gas to one of the other variables. Boyle: V 1/P Charles: V T Avogadro: V n We can put them all together to get 93 Ideal Gas Law V nt P To change from a proportionality,, to an equation, we introduce, R, the proportionality constant or Universal Gas Constant. 94 Ideal Gas Law Ideal Gas Law This makes the previous proportionality relationship into V = R*nT/P Or more commonly PV = nrt the IDEAL GAS EQUATION 95 The most common value of R is Latm MolK There are other values of R with different units that are listed in your book, but we ll use the one above. Note: they all are equivalent, it just depends on what unit (mostly pressure) you are using
17 Relationship to Other Gas Laws P 1 V 1 = P 2 V 2 n 1 T 1 n 2 T 2 Both equations are equal to a constant, which is R (the gas constant) 97 Ideal Gas Equation Example A deodorant can has a volume of L and a pressure of 3.80 atm at 22ºC. How many moles of gas are contained in the can? Given: P=3.80 atm; V = L; T=22+273=295 K; R = Latm/molK PV=nRT Looking for n (moles) So n = PV = (3.80 atm)(0.175 L) RT (0.0821L*atm/mol*K)*295K = mol 98 Ideal Gas Equation Practice Calculate the volume that a mol sample of gas will occupy at 265 K and atm. A 47.3 L container containing 1.62 mol of He is heated until the pressure reaches 1.85 atm. What is the temperature in ⁰C? Kr gas in a 18.5 L cylinder exerts a pressure of 8.61 atm at 24.8ºC What is the mass of Kr? 99 Gas Density and Molar Mass Let M stand for molar mass (g/mol) Where n = m/m ; m = mass in grams, n is moles And we know PV=nRT So then PV= (m/m)rt Rearranging gives: M = mrt V P Finally we get: M = drt/p Mass/volume = Density 100 Gas Density & Molar Mass Example 1 What is molar mass of a gas that has a density of 1.40 g/l at STP? Given: T=273; P=1.00 atm; d=1.40 g/l; R= Latm/molK Know M = DRT/P so =(1.40 g/l)( Latm/molK)(273K) 1.0 atm = 31.4 g/mol Dalton s Law of Partial Pressures Dalton s Law of Partial Pressure (end of Ch. 12.1) states that the total pressure of a mixture of gases is equal to the sum of the pressures of all the gases in the mixture. In other words P total = P 1 + P 2 + P 3 P n
18 Dalton s Law of Partial Pressures John Dalton Dalton s Law of Partial Pressures partial pressure depends only on: number of moles of gas container volume temperature of the gas. It does not depend on the identity of the gas. Because gas molecules are so far apart, they don t interact with each other Dalton s Law Example 1 We have a mixture of O 2, CO 2, and N 2 in a vessel at STP. The partial pressure of CO 2 is 0.70 atm and the partial pressure of N 2 is 0.12 atm. What is the partial pressure of O 2? Answer: What is total pressure? 1 atm, so 1.00 = P(O 2 ) P(O 2 ) = = 0.18 atm 105 Partial Pressure & Mole Fraction The partial pressure of a gas component in a mixture is dependent on how much (moles) are there: P a = n A RT/V The total pressure of a gas mixture is P total = n total RT/V 106 Partial Pressure & Mole Fraction Ratio of pressure of component to total gas pressure: = / / RT & V are constants so = Partial Pressure & Mole Fraction = This means that the partial pressure of a gas is equal to its mole fraction multiplied by the total pressure: P a = n a * P total Mole Fraction n total
19 Mole Fraction Example 1 A mixture of O 2, N 2, and He gases are in an enclosed tank. The total pressure in the tank is 12.3 atm. If there are 10.6 mol of N 2, 3.3 mol O 2 and 1.2 mol He in the tank, what is the partial pressure of each gas? 109 Mole Fraction Example 1 Find total Number of moles: = 15.1 mol gas total. For N 2 : P N2 = = 8.6 atm. For O 2 : P O2 = = 2.7 atm. For He: P He = = 1.0 atm. The sum of the pressures is 12.3 atm.110 Mole Fraction Example 2 A gas mixture containing mol He, mol Ne and mol Ar is confined to a 7.00 L vessel at 25 C. a) Calculate the partial pressure of each gas in the mixture b) Calculate the total pressure of the mixture. P(He) = mol( Latm/molK)(298K)/7.0 L = 1.88 atm P(Ne) = mol( Latm/molK)(298K)/7.0 L = 1.10 atm Mole Fraction Example 2 Can do previous problem because the gases are at same T & V. Therefore, their mole ratios will be proportional. Greater moles means greater partial pressure! P(Ar) = mol( Latm/molK)(298K)/7.0 L = 0.36 atm Tired of moles? So am I
Chapter 4. Chemical Composition. Chapter 4 Topics H 2 S. 4.1 Mole Quantities. The Mole Scale. Molar Mass The Mass of 1 Mole
Chapter 4 Chemical Composition Chapter 4 Topics 1. Mole Quantities 2. Moles, Masses, and Particles 3. Determining Empirical Formulas 4. Chemical Composition of Solutions Copyright The McGrawHill Companies,
More informationCHAPTER 8: CHEMICAL COMPOSITION
CHAPTER 8: CHEMICAL COMPOSITION Active Learning: 14, 68, 12, 1825; EndofChapter Problems: 34, 982, 8485, 8792, 94104, 107109, 111, 113, 119, 125126 8.2 ATOMIC MASSES: COUNTING ATOMS BY WEIGHING
More informationINTRODUCTORY CHEMISTRY Concepts and Critical Thinking
INTRODUCTORY CHEMISTRY Concepts and Critical Thinking Sixth Edition by Charles H. Corwin Chapter 9 The Mole Concept by Christopher Hamaker 2011 Pearson Education, Inc. Chapter 9 1 Avogadro s Number Avogadro
More informationChem. Ch. 10 ~ THE MOLE NOTE: Vocabulary terms are in boldface and underlined. Supporting details are in italics.
Chem. Ch. 10 ~ THE MOLE NOTE: Vocabulary terms are in boldface and underlined. Supporting details are in italics. 10.1 Notes I. Measuring Matter A. SI unit of chemical quantity = the mole (abbreviated
More informationStudy Guide For Chapter 7
Name: Class: Date: ID: A Study Guide For Chapter 7 Multiple Choice Identify the choice that best completes the statement or answers the question. 1. The number of atoms in a mole of any pure substance
More informationF321 MOLES. Example If 1 atom has a mass of 1.241 x 1023 g 1 mole of atoms will have a mass of 1.241 x 1023 g x 6.02 x 10 23 = 7.
Moles 1 MOLES The mole the standard unit of amount of a substance (mol) the number of particles in a mole is known as Avogadro s constant (N A ) Avogadro s constant has a value of 6.02 x 10 23 mol 1.
More informationChemical Calculations: The Mole Concept and Chemical Formulas. AW Atomic weight (mass of the atom of an element) was determined by relative weights.
1 Introduction to Chemistry Atomic Weights (Definitions) Chemical Calculations: The Mole Concept and Chemical Formulas AW Atomic weight (mass of the atom of an element) was determined by relative weights.
More informationMajor chemistry laws. Mole and Avogadro s number. Calculating concentrations.
Major chemistry laws. Mole and Avogadro s number. Calculating concentrations. Major chemistry laws Avogadro's Law Equal volumes of gases under identical temperature and pressure conditions will contain
More informationTutorial 6 GASES. PRESSURE: atmospheres or mm Hg; 1 atm = 760 mm Hg. STP: Standard Temperature and Pressure: 273 K and 1 atm (or 760 mm Hg)
T41 Tutorial 6 GASES Before working with gases some definitions are needed: PRESSURE: atmospheres or mm Hg; 1 atm = 760 mm Hg TEMPERATURE: Kelvin, K, which is o C + 273 STP: Standard Temperature and Pressure:
More informationCHEMISTRY GAS LAW S WORKSHEET
Boyle s Law Charles Law GuyLassac's Law Combined Gas Law For a given mass of gas at constant temperature, the volume of a gas varies inversely with pressure PV = k The volume of a fixed mass of gas is
More informationAS1 MOLES. oxygen molecules have the formula O 2 the relative mass will be 2 x 16 = 32 so the molar mass will be 32g mol 1
Moles 1 MOLES The mole the standard unit of amount of a substance the number of particles in a mole is known as Avogadro s constant (L) Avogadro s constant has a value of 6.023 x 10 23 mol 1. Example
More informationChemistry I: Using Chemical Formulas. Formula Mass The sum of the average atomic masses of all elements in the compound. Units are amu.
Chemistry I: Using Chemical Formulas Formula Mass The sum of the average atomic masses of all elements in the compound. Units are amu. Molar Mass  The mass in grams of 1 mole of a substance. Substance
More informationChapter 10 Chemical Quantities
Chapter 10 Chemical Quantities 101 The Mole: A Measurement 102 MoleMass and MoleVolume Relationships 103 Percent Composition and Chemical Formulas 1 Copyright Pearson Education, Inc, or its affiliates
More informationElement of same atomic number, but different atomic mass o Example: Hydrogen
Atomic mass: p + = protons; e  = electrons; n 0 = neutrons p + + n 0 = atomic mass o For carbon12, 6p + + 6n 0 = atomic mass of 12.0 o For chlorine35, 17p + + 18n 0 = atomic mass of 35.0 atomic mass
More informationCHEMICAL QUANTITIES. Chapter 10
CHEMICAL QUANTITIES Chapter 10 What is a mole? A unit of measurement in chemistry 1 mole of a substance = 6.02 x 10 23 (Avagadro s number) representative particles of a substance Representative particle
More informationName Date Class CHEMICAL QUANTITIES. SECTION 10.1 THE MOLE: A MEASUREMENT OF MATTER (pages 287 296)
10 CHEMICAL QUANTITIES SECTION 10.1 THE MOLE: A MEASUREMENT OF MATTER (pages 287 296) This section defines the mole and explains how the mole is used to measure matter. It also teaches you how to calculate
More informationHow much does a single atom weigh? Different elements weigh different amounts related to what makes them unique.
How much does a single atom weigh? Different elements weigh different amounts related to what makes them unique. What units do we use to define the weight of an atom? amu units of atomic weight. (atomic
More informationMole Notes.notebook. October 29, 2014
1 2 How do chemists count atoms/formula units/molecules? How do we go from the atomic scale to the scale of everyday measurements (macroscopic scale)? The gateway is the mole! But before we get to the
More informationChapter 7. Bellringer. Table of Contents. Chapter 7. Chapter 7. Objectives. Avogadro s Number and the Mole. Chapter 7. Chapter 7
The Mole and Chemical Table of Contents Chemical Formulas Bellringer List as many common counting units as you can. Determine how many groups of each unit in your list are present in each of the following
More informationChapter 3. Stoichiometry: Ratios of Combination. Insert picture from First page of chapter. Copyright McGrawHill 2009 1
Chapter 3 Insert picture from First page of chapter Stoichiometry: Ratios of Combination Copyright McGrawHill 2009 1 3.1 Molecular and Formula Masses Molecular mass  (molecular weight) The mass in amu
More informationThe Mole Concept. The Mole. Masses of molecules
The Mole Concept Ron Robertson r2 c:\files\courses\111020\2010 final slides for web\mole concept.docx The Mole The mole is a unit of measurement equal to 6.022 x 10 23 things (to 4 sf) just like there
More information= 16.00 amu. = 39.10 amu
Using Chemical Formulas Objective 1: Calculate the formula mass or molar mass of any given compound. The Formula Mass of any molecule, formula unit, or ion is the sum of the average atomic masses of all
More informationChapter 4 Chemical Composition. Moles of Various Elements and Compounds Figure 4.8
Chapter 4 Chemical Composition Mole Quantities Moles, Masses, and Particles Determining Empirical and Molecular Formulas Chemical Composition of Solutions 41 Copyright The McGrawHill Companies, Inc.
More informationThe Gas Laws. Our Atmosphere. Pressure = Units of Pressure. Barometer. Chapter 10
Our Atmosphere The Gas Laws 99% N 2 and O 2 78% N 2 80 70 Nitrogen Chapter 10 21% O 2 1% CO 2 and the Noble Gases 60 50 40 Oxygen 30 20 10 0 Gas Carbon dioxide and Noble Gases Pressure Pressure = Force
More informationThe Mole. 6.022 x 10 23
The Mole 6.022 x 10 23 Background: atomic masses Look at the atomic masses on the periodic table. What do these represent? E.g. the atomic mass of Carbon is 12.01 (atomic # is 6) We know there are 6 protons
More informationCalculating Atoms, Ions, or Molecules Using Moles
TEKS REVIEW 8B Calculating Atoms, Ions, or Molecules Using Moles TEKS 8B READINESS Use the mole concept to calculate the number of atoms, ions, or molecules in a sample TEKS_TXT of material. Vocabulary
More informationName Date Class CHEMICAL QUANTITIES. SECTION 10.1 THE MOLE: A MEASUREMENT OF MATTER (pages 287 296)
Name Date Class 10 CHEMICAL QUANTITIES SECTION 10.1 THE MOLE: A MEASUREMENT OF MATTER (pages 287 296) This section defines the mole and explains how the mole is used to measure matter. It also teaches
More informationChapter 7 Part II: Chemical Formulas and Equations. Mr. Chumbley Chemistry 12
Chapter 7 Part II: Chemical Formulas and Equations Mr. Chumbley Chemistry 12 SECTION 3: USING CHEMICAL FORMULAS Molecules and Formula Unit We have not yet discussed the different ways in which chemical
More informationPart One: Mass and Moles of Substance. Molecular Mass = sum of the Atomic Masses in a molecule
CHAPTER THREE: CALCULATIONS WITH CHEMICAL FORMULAS AND EQUATIONS Part One: Mass and Moles of Substance A. Molecular Mass and Formula Mass. (Section 3.1) 1. Just as we can talk about mass of one atom of
More informationChapter 4 Chemical Composition
Chapter 4 Chemical Composition 4.1 (a) mole; (b) Avogadro s number; (c) empirical formula; (d) solute; (e) molarity; (f) concentrated solution 4. (a) molar mass; (b) percent composition by mass; (c) solvent;
More informationChapter 3: Stoichiometry
Chapter 3: Stoichiometry Key Skills: Balance chemical equations Predict the products of simple combination, decomposition, and combustion reactions. Calculate formula weights Convert grams to moles and
More information2. If pressure is constant, the relationship between temperature and volume is a. direct b. Inverse
Name Unit 11 Review: Gas Laws and Intermolecular Forces Date Block 1. If temperature is constant, the relationship between pressure and volume is a. direct b. inverse 2. If pressure is constant, the relationship
More informationFormula Stoichiometry. Text pages
Formula Stoichiometry Text pages 237250 Formula Mass Review Write a chemical formula for the compound. H 2 CO 3 Look up the average atomic mass for each of the elements. H = 1.008 C= 12.01 O = 16.00 Multiply
More informationCHAPTER 11  CHEMICAL QUANTITIES
I. THE MOLE CONCEPT CHAPTER 11  CHEMICAL QUANTITIES A. What is a mole? 1. a mole is the SI unit of measurement of counting; just like a dozen is a measurement 2. a mole is a number a. 6.02 x 10 23 is
More informationCHEMISTRY. (i) It failed to explain how atoms of different elements differ from each other.
CHEMISTRY MOLE CONCEPT DALTON S ATOMIC THEORY By observing the laws of chemical combination, John Dalton proposed an atomic theory of matter. The main points of Dalton s atomic theory are as follows: (i)
More informationChapter 5. Quantities in Chemistry
Chapter 5 Quantities in Chemistry REMEMBER: You are required to use dimensional analysis whenever possible, which is almost all of the time in chemistry! If you choose not to use dimensional analysis,
More informationTOPIC 8. CHEMICAL CALCULATIONS II: % composition, empirical formulas.
TOPIC 8. CHEMICAL CALCULATIONS II: % composition, empirical formulas. Percentage composition of elements in compounds. In Topic 1 it was stated that a given compound always has the same composition by
More informationPercent Composition. Percent Composition the percentage by mass of each element in a compound. Percent = Part Whole x 100%
Percent Composition Percent Composition the percentage by mass of each element in a compound Percent = Part Whole x 100% Percent composition of a compound or = molecule Mass of element in 1 mol x 100%
More informationThe Mole Concept. A. Atomic Masses and Avogadro s Hypothesis
The Mole Concept A. Atomic Masses and Avogadro s Hypothesis 1. We have learned that compounds are made up of two or more different elements and that elements are composed of atoms. Therefore, compounds
More informationChemical Quantities: The Mole Chapter 7 Assignment & Problem Set
Chemical Quantities: The Mole Name WarmUps (Show your work for credit) Date 1. Date 2. Date 3. Date 4. Date 5. Date 6. Date 7. Date 8. Chemical Quantities: The Mole 2 Study Guide: Things You Must Know
More informationCh. 10 The Mole I. Molar Conversions
Ch. 10 The Mole I. Molar Conversions I II III IV A. What is the Mole? A counting number (like a dozen) Avogadro s number (N A ) 1 mole = 6.022 10 23 representative particles B. Mole/Particle Conversions
More informationCHAPTER 3 Calculations with Chemical Formulas and Equations. atoms in a FORMULA UNIT
CHAPTER 3 Calculations with Chemical Formulas and Equations MOLECULAR WEIGHT (M. W.) Sum of the Atomic Weights of all atoms in a MOLECULE of a substance. FORMULA WEIGHT (F. W.) Sum of the atomic Weights
More informationFormulas, Equations, and Moles. + "reacts with" "to produce" Equations must be balanced. Equal amounts of each element on each side of the equation.
Chapter 3 Formulas, Equations, and Moles Chemical Equations 2 2 + 2 2 2 reactants products + "reacts with" "to produce" coefficients  indicate amount of substance Equations must be balanced. Equal amounts
More informationStoichiometry Dr. M. E. Bridge
Preliminary Chemistry Course Stoichiometry Dr. M. E. Bridge What is stoichiometry? The meaning of the word: The word stoichiometry comes from two Greek words: (meaning element ) and (meaning measure )
More information602X10 21 602,000,000,000, 000,000,000,000 6.02X10 23. Pre AP Chemistry Chemical Quan44es: The Mole. Diatomic Elements
Pre AP Chemistry Chemical Quan44es: The Mole Mole SI unit of measurement that measures the amount of substance. A substance exists as representa9ve par9cles. Representa9ve par9cles can be atoms, molecules,
More information10 The Mole. Section 10.1 Measuring Matter
Name Date Class The Mole Section.1 Measuring Matter In your textbook, read about counting particles. In Column B, rank the quantities from Column A from smallest to largest. Column A Column B 0.5 mol 1.
More informationATOMS. Multiple Choice Questions
Chapter 3 ATOMS AND MOLECULES Multiple Choice Questions 1. Which of the following correctly represents 360 g of water? (i) 2 moles of H 2 0 (ii) 20 moles of water (iii) 6.022 10 23 molecules of water (iv)
More informationFigure 10.3 A mercury manometer. This device is sometimes employed in the laboratory to measure gas pressures near atmospheric pressure.
Characteristics of Gases Practice Problems A. Section 10.2 Pressure Pressure Conversions: 1 ATM = 101.3 kpa = 760 mm Hg (torr) SAMPLE EXERCISE 10.1 Converting Units of Pressure (a) Convert 0.357 atm to
More informationChemical Calculations: Formula Masses, Moles, and Chemical Equations
Chemical Calculations: Formula Masses, Moles, and Chemical Equations Atomic Mass & Formula Mass Recall from Chapter Three that the average mass of an atom of a given element can be found on the periodic
More information2 The Structure of Atoms
CHAPTER 4 2 The Structure of Atoms SECTION Atoms KEY IDEAS As you read this section, keep these questions in mind: What do atoms of the same element have in common? What are isotopes? How is an element
More informationDescription of the Mole Concept:
Description of the Mole Concept: Suppose you were sent into the store to buy 36 eggs. When you picked them up you would get 3 boxes, each containing 12 eggs. You just used a mathematical device, called
More information= 1.038 atm. 760 mm Hg. = 0.989 atm. d. 767 torr = 767 mm Hg. = 1.01 atm
Chapter 13 Gases 1. Solids and liquids have essentially fixed volumes and are not able to be compressed easily. Gases have volumes that depend on their conditions, and can be compressed or expanded by
More informationCalculation of Molar Masses. Molar Mass. Solutions. Solutions
Molar Mass Molar mass = Mass in grams of one mole of any element, numerically equal to its atomic weight Molar mass of molecules can be determined from the chemical formula and molar masses of elements
More informationTOPIC 8. CHEMICAL CALCULATIONS II: % composition, empirical formulas.
TOPIC 8. CHEMICAL CALCULATIONS II: % composition, empirical formulas. Percentage composition of elements in compounds. In Topic 1 it was stated that a given compound always has the same composition by
More informationUnit 2. Molar Mass Worksheet
Unit 2 Molar Mass Worksheet Calculate the molar masses of the following chemicals: 1) Cl 2 8) UF 6 2) KOH 9) SO 2 3) BeCl 2 10) H 3 PO 4 4) FeCl 3 11) (NH 4 ) 2 SO 4 5) BF 3 12) CH 3 COOH 6) CCl 2 F 2
More informationCHE141 Chapter 10. Chapter 10 Gases
Chapter 0 Gases. A sample of gas (4.g) initially at 4.00 atm was compressed from 8.00 L to.00 L at constant temperature. After the compression, the gas pressure was atm. (a). 4.00 (b)..00 (c)..00 (d).
More informationMOLECULAR MASS AND FORMULA MASS
1 MOLECULAR MASS AND FORMULA MASS Molecular mass = sum of the atomic weights of all atoms in the molecule. Formula mass = sum of the atomic weights of all atoms in the formula unit. 2 MOLECULAR MASS AND
More informationName Block THE MOLE. Who s Counting Lab. Mole Notes. Mole Calculations. Mixed Mole Conversions. % Comp, Emp, and Molecular Calcuations
Name Block THE MOLE Who s Counting Lab Mole Notes Mole Calculations Mixed Mole Conversions % Comp, Emp, and Molecular Calcuations Mole Notes, Part 1 1. The Mole is just a long word for changing units
More information1. How many hydrogen atoms are in 1.00 g of hydrogen?
MOLES AND CALCULATIONS USING THE MOLE CONCEPT INTRODUCTORY TERMS A. What is an amu? 1.66 x 1024 g B. We need a conversion to the macroscopic world. 1. How many hydrogen atoms are in 1.00 g of hydrogen?
More informationExploring Gas Laws. Chapter 12. Solutions for Practice Problems. Student Textbook page 477
Chapter 12 Exploring Gas Laws Solutions for Practice Problems Student Textbook page 477 1. Problem At 19 C and 100 kpa, 0.021 mol of oxygen gas, O 2(g), occupy a volume of 0.50 L. What is the molar volume
More informationThe Mole IT IS JUST A STANDARD NUMBER OF ATOMS/MOLECULES
The Mole S 6.02 X 10 23 IT IS JUST A STANDARD NUMBER OF ATOMS/MOLECULES Relative Masses To understand relative scales, let s s ignore electrons and compare atoms by total number of nuclear particles. Hydrogen,
More informationChapter 1: Moles and equations. Learning outcomes. you should be able to:
Chapter 1: Moles and equations 1 Learning outcomes you should be able to: define and use the terms: relative atomic mass, isotopic mass and formula mass based on the 12 C scale perform calculations, including
More informationExample Problems. PV nt =R so P i. V i n i T i. = P f V f n f T f. (since V and n are constant) = P f T f. T i
The temperature of 2.5 L of a gas initially at STP is raised to 250 o C at constant volume. Calculate the final pressure of the gas in atm. PV nt =R so P i V i n i T i = P f V f n f T f or P i T i = P
More informationUnit 3 Notepack Chapter 7 Chemical Quantities Qualifier for Test
Unit 3 Notepack Chapter 7 Chemical Quantities Qualifier for Test NAME Section 7.1 The Mole: A Measurement of Matter A. What is a mole? 1. Chemistry is a quantitative science. What does this term mean?
More informationW1 WORKSHOP ON STOICHIOMETRY
INTRODUCTION W1 WORKSHOP ON STOICHIOMETRY These notes and exercises are designed to introduce you to the basic concepts required to understand a chemical formula or equation. Relative atomic masses of
More informationStoichiometry. What is the atomic mass for carbon? For zinc?
Stoichiometry Atomic Mass (atomic weight) Atoms are so small, it is difficult to discuss how much they weigh in grams We use atomic mass units an atomic mass unit (AMU) is one twelfth the mass of the catbon12
More informationAtomic mass and the mole
Atomic mass and the mole An equation for a chemical reaction can provide us with a lot of useful information. It tells us what the reactants and the products are in the reaction, and it also tells us the
More informationA dozen. Molar Mass. Mass of atoms
A dozen Molar Mass Science 10 is a number of objects. A dozen eggs, a dozen cars, and a dozen people are all 12 objects. But a dozen cars has a much greater mass than a dozen eggs because the mass of each
More informationChemical Composition. Introductory Chemistry: A Foundation FOURTH EDITION. Atomic Masses. Atomic Masses. Atomic Masses. Chapter 8
Introductory Chemistry: A Foundation FOURTH EDITION by Steven S. Zumdahl University of Illinois Chemical Composition Chapter 8 1 2 Atomic Masses Balanced equation tells us the relative numbers of molecules
More information21 st Century Chemistry Multiple Choice Question in Topic 3 Metals Unit 11
21 st Century Chemistry Multiple Choice Question in Topic 3 Metals Unit 11 1. Consider the equation: 2Ca(s) + O 2 (g) 2CaO(s) Which of the following statements are correct? (1) Calcium and oxygen are reactants.
More informationFormulas, Equations and Moles
Chapter 3 Formulas, Equations and Moles Interpreting Chemical Equations You can interpret a balanced chemical equation in many ways. On a microscopic level, two molecules of H 2 react with one molecule
More informationWe know from the information given that we have an equal mass of each compound, but no real numbers to plug in and find moles. So what can we do?
How do we figure this out? We know that: 1) the number of oxygen atoms can be found by using Avogadro s number, if we know the moles of oxygen atoms; 2) the number of moles of oxygen atoms can be found
More information1. P 2 O 5 2. P 5 O 2 3. P 10 O 4 4. P 4 O 10
Teacher: Mr. gerraputa Print Close Name: 1. A chemical formula is an expression used to represent 1. mixtures, only 3. compounds, only 2. elements, only 4. compounds and elements 2. What is the total number
More informationChemical Composition Review Mole Calculations Percent Composition. Copyright Cengage Learning. All rights reserved. 8 1
Chemical Composition Review Mole Calculations Percent Composition Copyright Cengage Learning. All rights reserved. 8 1 QUESTION Suppose you work in a hardware store and a customer wants to purchase 500
More informationMole Concept and Stoichiometry
1 Mole Concept and Stoichiometry Concept Mole Concept Introduction This is our common experience that when we go to market to buy something, a few things we always get in definite numbers. For example,
More informationMULTIPLE CHOICE 1. What are standard temperature and pressure conditions for gases?
Gas Laws MULTIPLE CHOICE 1. What are standard temperature and pressure conditions for gases? a. 0 C and 0 torr b. 0 K and 760 torr c. 273 C and 1 atm d. 0 C and 760 torr e. 0 C and 1 torr 2. If the volume
More informationExam 4 Practice Problems false false
Exam 4 Practice Problems 1 1. Which of the following statements is false? a. Condensed states have much higher densities than gases. b. Molecules are very far apart in gases and closer together in liquids
More informationPercent Composition  Formulas
Percent Composition  Formulas This program demonstrates how to find percentage composition as well as empirical and molecular formulas from that data. Please read each section carefully. You might wish
More informationGas particles move in straight line paths. As they collide, they create a force, pressure.
#28 notes Unit 4: Gases Ch. Gases I. Pressure and Manometers Gas particles move in straight line paths. As they collide, they create a force, pressure. Pressure = Force / Area Standard Atmospheric Pressure
More information2/15/2013. Chapter
Chapter 10 1 10.1 You could measure the amount of sand in a sand sculpture by counting each grain of sand, but it would be much easier to weigh the sand. You ll discover how chemists measure the amount
More informationForce. Pressure = ; Area. Force = Mass times Acceleration;
Force Pressure = ; Area Force = Mass times Acceleration; If mass = kg, and acceleration = m/s 2, Force = kg.m/s 2 = Newton (N) If Area = m 2, Pressure = (kg.m/s 2 )/m 2 = N/m 2 = Pascal; (1 Pa = 1 N/m
More informationStoichiometry. 1. The total number of moles represented by 20 grams of calcium carbonate is (1) 1; (2) 2; (3) 0.1; (4) 0.2.
Stoichiometry 1 The total number of moles represented by 20 grams of calcium carbonate is (1) 1; (2) 2; (3) 01; (4) 02 2 A 44 gram sample of a hydrate was heated until the water of hydration was driven
More informationChapter 1 The Atomic Nature of Matter
Chapter 1 The Atomic Nature of Matter 6. Substances that cannot be decomposed into two or more simpler substances by chemical means are called a. pure substances. b. compounds. c. molecules. d. elements.
More informationNotes: Formula Mass and Percent Composition
Notes: Formula Mass and Percent Composition Formula mass  the mass of one mole of a compound, atom or ion. also called: gram formula mass, molecular mass, gram molecular mass, formula weight, gram formula
More informationChapter 3! Stoichiometry: Calculations with Chemical Formulas and Equations. Stoichiometry
Chapter 3! : Calculations with Chemical Formulas and Equations Anatomy of a Chemical Equation CH 4 (g) + 2O 2 (g) CO 2 (g) + 2 H 2 O (g) Anatomy of a Chemical Equation CH 4 (g) + 2 O 2 (g) CO 2 (g) + 2
More informationChapter 4. The Mole Concept
Chapter 4. The Mole Concept Introduction If you were to take one volume (Eg. 1cm 3 ) of every element, weigh them and rank them according to their weights you would discover that they followed the periodic
More informationMole Relationships in Chemistry
Mole Relationships in Chemistry The Mole Concept and Atomic Masses The mole concept and molar mass is historically based on two laws from JosephLouis Proust in 1797 The Law of Definite Proportions This
More informationThe Mole Concept and Atoms
Copyright The McGrawHill Companies, Inc. Permission required for reproduction or display. Chapter 4 24 September 2013 Calculations and the Chemical Equation The Mole Concept and Atoms Atoms are exceedingly
More informationOther Stoich Calculations A. mole mass (mass mole) calculations. GIVEN mol A x CE mol B. PT g A CE mol A MOLE MASS :
Chem. I Notes Ch. 12, part 2 Using Moles NOTE: Vocabulary terms are in boldface and underlined. Supporting details are in italics. 1 MOLE = 6.02 x 10 23 representative particles (representative particles
More informationChapter 6 Notes. Chemical Composition
Chapter 6 Notes Chemical Composition Section 6.1: Counting By Weighing We can weigh a large number of the objects and find the average mass. Once we know the average mass we can equate that to any number
More information1. Balance the following equation. What is the sum of the coefficients of the reactants and products?
1. Balance the following equation. What is the sum of the coefficients of the reactants and products? 1 Fe 2 O 3 (s) + _3 C(s) 2 Fe(s) + _3 CO(g) a) 5 b) 6 c) 7 d) 8 e) 9 2. Which of the following equations
More informationChapter 3. Chemical Reactions and Reaction Stoichiometry. Lecture Presentation. James F. Kirby Quinnipiac University Hamden, CT
Lecture Presentation Chapter 3 Chemical Reactions and Reaction James F. Kirby Quinnipiac University Hamden, CT The study of the mass relationships in chemistry Based on the Law of Conservation of Mass
More informationCHAPTER. Copyright by Holt, Rinehart and Winston. All rights reserved.
CHAPTER 222 Galaxies have hundreds of billions of stars. The universe may have as many as sextillion stars that s 1000 000 000 000 000 000 000 (or 1 10 21 ) stars. Such a number is called astronomical
More informationThe Mole. Chapter 2. Solutions for Practice Problems
Chapter 2 The Mole Note to teacher: You will notice that there are two different formats for the Sample Problems in the student textbook. Where appropriate, the Sample Problem contains the full set of
More informationThe mass of the formula unit is called the formula mass Formula masses are calculated the same way as molecular masses
Chapter 4: The Mole Atomic mass provides a means to count atoms by measuring the mass of a sample The periodic table on the inside cover of the text gives atomic masses of the elements The mass of an atom
More informationAbbreviations Conversions Standard Conditions Boyle s Law
Gas Law Problems Abbreviations Conversions atm  atmosphere K = C + 273 mmhg  millimeters of mercury 1 cm 3 (cubic centimeter) = 1 ml (milliliter) torr  another name for mmhg 1 dm 3 (cubic decimeter)
More informationCONSERVATION OF MASS During a chemical reaction, matter is neither created nor destroyed.  i. e. the number of atoms of each element remains constant
1 CHEMICAL REACTINS Example: Hydrogen + xygen Water H + H + +  Note there is not enough hydrogen to react with oxygen  It is necessary to balance equation. reactants products + H + H (balanced equation)
More informationWoods Chem1 Lec02 101 Atoms, Ions, Mole (std) Page 1 ATOMIC THEORY, MOLECULES, & IONS
Woods Chem1 Lec02 101 Atoms, Ions, Mole (std) Page 1 ATOMIC THEORY, MOLECULES, & IONS Proton: A positively charged particle in the nucleus Atomic Number: We differentiate all elements by their number
More informationChapter 5. Name: Class: Date: Multiple Choice Identify the choice that best completes the statement or answers the question.
Class: Date: Chapter 5 Multiple Choice Identify the choice that best completes the statement or answers the question. 1. What is the pressure of the sample of gas trapped in the opentube mercury manometer
More informationSample Exercise 10.1 Converting Pressure Units
Sample Exercise 10.1 Converting Pressure Units (a) Convert 0.357 atm to torr. (b) Convert 6.6 10 2 torr to atmospheres. (c) Convert 147.2 kpa to torr. Solution Analyze In each case we are given the pressure
More information