SOME BASIC CONCEPTS OF CHEMISTRY
|
|
|
- Elfreda Bryan
- 7 years ago
- Views:
Transcription
1 SOME BASIC CONCEPTS OF CHEMISTRY Type I : Law of Conservation of Mass In all physical and chemical changes the total mass of reactants is equal to that of products. 1. What mass of AgNO will react with 5.85 g NaCl to produce 14.5 g AgCl and 8.5 g NaNO, if law of conservation is true? Ans. AgNO + NaCl AgCl + NaNO x 5.85 g 14.5 g 8.5 g Here, x = x = 17.0 g 2. If 6. g of NaHCO are added to 15.0 g of CH COOH, the residue is found to be 18.0 g. What is the mass of CO 2 released? Ans. CHCOOH + NaHCO CHCOONa + H2O + CO2 [. gm] Type II : Law of Constant Composition or Definite proportions g of Cu-metal when treated with nitric acid followed by ignition of nitrate gave 2.70 g of copper-oxide, In another experiment 1.15 g of copper oxide upon reduction with hydrogen gave 0.92 g Cu. Show that this illustrates law of definite proportions. Ans. i) % of Cu in CuO = = 80 % Oxygen = 20 % ii) % of Cu in 2 nd experiment = = 80 % Oxygen = 20 % As % is same in both, law is obeyed. 4. Silver chloride is prepared by, i) Dissolving 0.5 g of silver wire in HNO and adding excess HCl to AgNO formed. The weight of this dried AgCl is 0.66 g. ii) Heating 1 g of silver metal in a current of dry chlorine gas till metal is completely converted to its chloride. It is found to weigh 1.2 g. Show that these data obey law of constant composition. 1
2 Type III : Law of Multiple proportions 5. Two oxides of metal contain 27.6 % and 0.0 % of oxygen respectively. If the formula of 1 st oxide is M O 4, find that of the second. Ans. 1 st oxide Mass of oxygen : 27.6 Mass of metal : = nd oxide Mass of oxygen : 0 Mass of metal : = 70 Formula of 1 st oxide : M O 4 No. of atoms of metal in 2 nd oxide = = 2.9 No. of atoms of oxygen in 2 nd oxide = = 4.5 Ratio of metal : oxygen in 2 nd oxide = 2.9 : 4.5 or 2 : Formula of 2 nd oxide is M 2O. 6. Copper gives two oxides. On heating 7.0 g of each in hydrogen gas g and g of metal are produced. Show that the results obey law of multiple proportions. 7. A metal forms two oxides. One contains % of metal and other contains 6.94 % metal. Show that the results are as per law of multiple proportions. Type IV : Law of Reciprocal proportion 8. Ammonia contains 82.5 % nitrogen and % hydrogen. Water contains 88.9% oxygen and 11.1 % hydrogen. Nitrogen trioxide contains 6.15 % oxygen and 6.85 % of nitrogen. Show that these data are as per law of reciprocal proportion. Ans. In NH, NH H 2 O g of H combines with N O 2 = 4.67 g of nitrogen In H 2O, 1 g of H combines with = 8.01 g of oxygen 11.1 Ratio of mass of N and O combining with 1 g H = 4.67 : 8.01 or 1 : 1.72 Ratio of N and O in N 2O = 6.85 : 6.15 or 1 : Ratios are same. 9. CO 2 contains % carbon, CS 2 contains % of carbon and SO 2 contains 50 % of sulpher. Are these data in agreement with law of reciprocal proportion? 2
3 g A combines with 80 g B. 0.9 g of A combine with g of C. B and C combine to form compound CB2. Atomic weights of C and B are respectively 5.5 and 6.6. Show that these data are in accordance with law of reciprocal proportion. Type V : Calculating average atomic mass 11. Chlorine has two isotopes of a.m.u and 6.97 respectively. The relative abundances of these isotopes are and respectively. Find average atomic mass of chlorine. Ans. Average atomic mass = ( ) + ( ) = Naturally occurring Boron consists of two isotopes whose atomic masses are and respectively. The atomic mass of natural Boron is Calculate percentage of each isotope in natural boron. Ans. 20 % and 80 % Type VI : Calculating mass of single atom or molecule Molar mass Mass of single atom or molecule = ( ) N A 1. Calculate mass of i) One atom of Ag ii) One molecule of CO 2. Molar mass of Ag 108 Ans. i) Mass of 1 atom of Ag = = 2 ( N A ) = g Molar mass of CO2 44 ii) Mass of 1 molecule of CO 2 = ( N A ) = g = 2 Type VII : Calculation of no. of atoms or molecules in a given mass of substance No. of atoms or molecules = No. of moles N A 14. How many atoms or molecules of sulpher are present in 64.0 g sulpher (S 8)? g Ans. Molar mass of sulpher (S 8) = 8 2 = 256 mol 64 No. of moles of S 8 = 256 = 0.25 No. of molecules = = molecules No. of S-atoms = = atoms
4 15. Calculate no. of molecules present in i) 4.20 g of cane-sugar (C12H22O11) ii) One drop of water having mass 0.05 g Ans and respectively 16. Calculate no. of atoms of all constituent elements in 5 g Na 2CO. Ans. Na= ions; C= ; O= Type VIII : Calculating no. of atoms and molecules in given volume of gas No. of moles of a gas at STP or NTP = Vol. of gas in litres Calculate the mass of i) molecules of methane ii) 112 cm (ml) of hydrogen at STP. 18. Calculate the volume occupied at STP by, i) 14 g of Nitrogen ii) 1.5 moles of CO 2 iii) molecules of Oxygen Ans L,.6 L, 7.2 ml 19. Calculate no. of moles of each in following i) 10 g of CaCO ii) molecules of CO2 Ans. 0.1, Calculate the mass of CO 2 which contains the same no. of molecules as are in 40 g of Oxygen. Ans. 55 g 21. Calculate the mass of Na2CO which will have the same no. of molecules as are in 12. g of MgSO4.7H2O. Ans. 5. g 22. Calculate the volume occupied at STP by, i) 16.0 g of Oxygen ii) 1.5 moles of Oxygen iii) molecules of CO 2 Ans L,.60 L, 22.4 L 2. Calculate the total no. of electrons present in 1.4 g of nitrogen gas. [Hint: each molecule of N2 has 14 electrons] Ans electrons 4
5 atoms of Fe weigh as much as 1 cc of H2 at STP. What is the atomic mass of iron? Ans Chlorophyll contains 2.68 % of magnesium by mass. Calculate the no. of magnesium atoms in 2.0 g chlorophyll. Ans Type IX : Calculation of Molarity and Normality of solution obtained upon mixing two or more solutions M1V 1 + M2V M = V + V N = N1V 1 + N2V V + V Calculate molarities and normalities of the solutions obtained on mixing (i) 100 ml 0.2 M H 2SO ml 0.1 M HCl M1V 1 + M2V2 ( ) + (50 0.1) Ans. M = = = M V 1 + V2 150 N1V 1 + N2V2 ( ) + (50 0.1) N = = = 0. N V 1 + V2 150 [Note: 0.2 M H2SO4 = 0.4 N H2SO4; 0.1 M HCl = 0.1 N HCl] 27. Calculate molarities and normalities of solutions obtained upon mixing (i) 100 ml 0.2 N H 2SO ml 0.1 N HCl Type X : Calculations based on Normality and Molarity Mass of solute dissolved in grams 1 Normality = Equivalent mass Volume of solution in litres Mass of solute dissolved in grams 1 Molarity = Molecular mass of solute Volume of solution in litres Molarity n = Normality 28. Calculate molarity of water if its density is 1000 kg/m. kg g g Ans. d = 1000 = = 1 m ml ml 1 lit. vol. of water has 1000 g No. of moles of water present in 1 lit = = M 5
6 29. A solution of oxalic acid (COOH)2.2H2O is prepared by dissolving 0.6 g of acid in 250 cm of solution. Calculate (i) molarity and (ii) normality. g [Mol. mass of (COOH)2.2H2O = 12.6 ] mol Ans. Molarity = = 0.02 M Normality = Molarity n = = 0.04 N 0. Commercially available conc. HCl contains 8% HCl by mass. Find g molarity.[density=1.19 cm ] Ans. 8% by mass = 8 g HCl in 100 g solution 8 g HCl in 100 ml = 84 ml solution Molarity = = 12.9 M Type XI : If a solution of fixed concentration is diluted then final normality/molarity can be calculated as Initial Conc. Final Conc. = M V M V or N 1 V1 = N 2 V2 1. What volume of 12.8 M HCl is needed to make 1.00 L solution of 0.1 M? Ans. M1V1 = M2V V1 = = 8.07 ml Concentrated H 2SO 4 is 98% by mass having density of 1.84 g/cc. What volume of H 2SO 4 is needed to make 5.0 litre solution of 0.5 M? Find molarity of H 2SO 4 solution. Ans. 98% = 98 g H2SO4 in 100 g solution 98 g H 2SO 4 in 100 = 54.4 ml solution Molarity = = 18.4 M Now, M 1V 1 = M 2V 2 V1 = = L = 15.8 ml. A sample of NaOH weighing 0.40 g is dissolved in water and the solution is made to 50.0 cm in volumetric flask. What is the molarity of resulting solution? Ans. 0.2 M 6
7 4. How many moles and how many grams of NaCl are present in 250 cm of a 0.50 M NaCl solution? Ans mole; 7.12 g 5. In a reaction vessel, g NaOH is required to be added for completing the reaction. How many millilitres of M NaOH solution should be added? Ans. 0.7 ml Type XII : Finding molality, mass-percent and mole fraction Mass of solute dissolved in grams 1 Molality = Mol. mass of solute Mass of solvent in kg Moles of solute Mole fraction of solute = Moles of solute + moles of solvent Mass of solute Mass-percent = 100 Mass of solution 6. A solution is prepared by adding 2 g of substance A to 18 g water. Calculate mass-percent. 2 Ans. Mass-percent = 100 [2 + 18] = 10% 7. Calculate mole-fraction of solute in 1 molal aqueous solution. Ans. 1 molal aqueous solution = 1 mole solute in 1000 g H 2O 1 1 Mole fraction of solute = = 1000 [1 + ] 56.5 = g 8. The density of M solution of NaCl is 1.25.Calculate molality of solution. ml Ans. molar solution = moles NaCl in 1000 ml solution For molality, mass of solute and mass of solvent are needed. From the given data, Mass of NaCl in solution = 58.5[mol. mass of NaCl] = g Mass of solution = volume density = = 1250 g Mass of solvent = [Mass of solution-mass of solute] = [ ] g = g Molality = = 2.79 m What is the mass percent of solute in the solution obtained by dissolving 5 g of solute in 50 g of water? Ans. 9.1 % 7
8 Type XIII : Calculations involving acid-solution mixed with a base solution When acid is neutralized by a base then, Equivalents of acid = Equivalents of base i) Finding equivalents in solution of given concentration Vol. of solution in litres Normality = Equivalents ii) Finding equivalents if mass is given in grams Mass of substance given in grams Equivalents = Equivalent mass of substance 40. Calculate normality and molarity of solution obtained by mixing: (a) 100 ml 0.1 M H 2SO ml 0.1 M NaOH (b) 50 ml 0.1 N H 2SO ml 0.1 N HCl Ans. (a) Equivalents of 0.1 M H 2SO M H2SO4 = 0.2 N H2SO4 [n=2] Equivalents = = 0.02 Equivalents of 50 ml 0.1 M NaOH 0.1 M NaOH = 0.1 N NaOH [n=1] Equivalents = = Equivalents of H2SO4 = Left unneutralized = Equivalents Normality of H2SO4 = = = 0.1 Normality = 0.1 N Molarity = = 0.05 M (b) Same as [a] [0.0 N; 0.0 M] Vol. of solution in litres Two acids H 2SO 4 and H PO 4 are neutralized separately by same amount of alkali when sulphate and dihydrogen orthophosphate are formed respectively. Find ratio of mass of H 2SO 4 and H PO 4. Ans. 1 : 2 Success seems to be largely a matter of hanging on after others have let go. 8
2. ATOMIC, MOLECULAR AND EQUIVALENT MASSES
2. ATOMIC, MOLECULAR AND EQUIVALENT MASSES INTRODUCTION: EQUIVALENT WEIGHT Since hydrogen is the lightest of all elements, it was chosen as a standard for determination of equivalent weights. On this basis,
Multiple Choice questions (one answer correct)
Mole Concept Multiple Choice questions (one answer correct) (1) Avogadro s number represents the number of atoms in (a) 12g of C 12 (b) 320g of sulphur (c) 32g of oxygen (d) 12.7g of iodine (2) The number
Liquid phase. Balance equation Moles A Stoic. coefficient. Aqueous phase
STOICHIOMETRY Objective The purpose of this exercise is to give you some practice on some Stoichiometry calculations. Discussion The molecular mass of a compound is the sum of the atomic masses of all
Chem 31 Fall 2002. Chapter 3. Stoichiometry: Calculations with Chemical Formulas and Equations. Writing and Balancing Chemical Equations
Chem 31 Fall 2002 Chapter 3 Stoichiometry: Calculations with Chemical Formulas and Equations Writing and Balancing Chemical Equations 1. Write Equation in Words -you cannot write an equation unless you
Chemistry B11 Chapter 4 Chemical reactions
Chemistry B11 Chapter 4 Chemical reactions Chemical reactions are classified into five groups: A + B AB Synthesis reactions (Combination) H + O H O AB A + B Decomposition reactions (Analysis) NaCl Na +Cl
Formulae, stoichiometry and the mole concept
3 Formulae, stoichiometry and the mole concept Content 3.1 Symbols, Formulae and Chemical equations 3.2 Concept of Relative Mass 3.3 Mole Concept and Stoichiometry Learning Outcomes Candidates should be
Stoichiometry Review
Stoichiometry Review There are 20 problems in this review set. Answers, including problem set-up, can be found in the second half of this document. 1. N 2 (g) + 3H 2 (g) --------> 2NH 3 (g) a. nitrogen
IB Chemistry. DP Chemistry Review
DP Chemistry Review Topic 1: Quantitative chemistry 1.1 The mole concept and Avogadro s constant Assessment statement Apply the mole concept to substances. Determine the number of particles and the amount
Chemical 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.
Element 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 carbon-12, 6p + + 6n 0 = atomic mass of 12.0 o For chlorine-35, 17p + + 18n 0 = atomic mass of 35.0 atomic mass
Calculation 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
Unit 6 The Mole Concept
Chemistry Form 3 Page 62 Ms. R. Buttigieg Unit 6 The Mole Concept See Chemistry for You Chapter 28 pg. 352-363 See GCSE Chemistry Chapter 5 pg. 70-79 6.1 Relative atomic mass. The relative atomic mass
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 McGraw-Hill Companies,
CHEMICAL REACTIONS AND REACTING MASSES AND VOLUMES
CHEMICAL REACTIONS AND REACTING MASSES AND VOLUMES The meaning of stoichiometric coefficients: 2 H 2 (g) + O 2 (g) 2 H 2 O(l) number of reacting particles 2 molecules of hydrogen react with 1 molecule
W1 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
Chemistry: Chemical Equations
Chemistry: Chemical Equations Write a balanced chemical equation for each word equation. Include the phase of each substance in the equation. Classify the reaction as synthesis, decomposition, single replacement,
Unit 2: Quantities in Chemistry
Mass, Moles, & Molar Mass Relative quantities of isotopes in a natural occurring element (%) E.g. Carbon has 2 isotopes C-12 and C-13. Of Carbon s two isotopes, there is 98.9% C-12 and 11.1% C-13. Find
Chapter 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
1. 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 10-24 g B. We need a conversion to the macroscopic world. 1. How many hydrogen atoms are in 1.00 g of hydrogen?
Aqueous Solutions. Water is the dissolving medium, or solvent. Some Properties of Water. A Solute. Types of Chemical Reactions.
Aqueous Solutions and Solution Stoichiometry Water is the dissolving medium, or solvent. Some Properties of Water Water is bent or V-shaped. The O-H bonds are covalent. Water is a polar molecule. Hydration
Solution. Practice Exercise. Concept Exercise
Example Exercise 9.1 Atomic Mass and Avogadro s Number Refer to the atomic masses in the periodic table inside the front cover of this textbook. State the mass of Avogadro s number of atoms for each of
Stoichiometry. Web Resources Chem Team Chem Team Stoichiometry. Section 1: Definitions Define the following terms. Average Atomic mass - Molecule -
Web Resources Chem Team Chem Team Section 1: Definitions Define the following terms Average Atomic mass - Molecule - Molecular mass - Moles - Avagadro's Number - Conservation of matter - Percent composition
MOLES AND MOLE CALCULATIONS
35 MOLES ND MOLE CLCULTIONS INTRODUCTION The purpose of this section is to present some methods for calculating both how much of each reactant is used in a chemical reaction, and how much of each product
Writing and Balancing Chemical Equations
Name Writing and Balancing Chemical Equations Period When a substance undergoes a chemical reaction, chemical bonds are broken and new bonds are formed. This results in one or more new substances, often
Chapter 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.
6 Reactions in Aqueous Solutions
6 Reactions in Aqueous Solutions Water is by far the most common medium in which chemical reactions occur naturally. It is not hard to see this: 70% of our body mass is water and about 70% of the surface
Chem 1100 Chapter Three Study Guide Answers Outline I. Molar Mass and Moles A. Calculations of Molar Masses
Chem 1100 Chapter Three Study Guide Answers Outline I. Molar Mass and Moles A. Calculations of Molar Masses B. Calculations of moles C. Calculations of number of atoms from moles/molar masses 1. Avagadro
Chemistry 51 Chapter 8 TYPES OF SOLUTIONS. A solution is a homogeneous mixture of two substances: a solute and a solvent.
TYPES OF SOLUTIONS A solution is a homogeneous mixture of two substances: a solute and a solvent. Solute: substance being dissolved; present in lesser amount. Solvent: substance doing the dissolving; present
Other 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
stoichiometry = the numerical relationships between chemical amounts in a reaction.
1 REACTIONS AND YIELD ANSWERS stoichiometry = the numerical relationships between chemical amounts in a reaction. 2C 8 H 18 (l) + 25O 2 16CO 2 (g) + 18H 2 O(g) From the equation, 16 moles of CO 2 (a greenhouse
1. When the following equation is balanced, the coefficient of Al is. Al (s) + H 2 O (l)? Al(OH) 3 (s) + H 2 (g)
1. When the following equation is balanced, the coefficient of Al is. Al (s) + H 2 O (l)? Al(OH) (s) + H 2 (g) A) 1 B) 2 C) 4 D) 5 E) Al (s) + H 2 O (l)? Al(OH) (s) + H 2 (g) Al (s) + H 2 O (l)? Al(OH)
AS1 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
ATOMS. 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)
Study 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
Chemical 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
Balancing Chemical Equations Worksheet
Balancing Chemical Equations Worksheet Student Instructions 1. Identify the reactants and products and write a word equation. 2. Write the correct chemical formula for each of the reactants and the products.
Number of moles of solute = Concentration (mol. L ) x Volume of solution (litres) or n = C x V
44 CALCULATIONS INVOLVING SOLUTIONS INTRODUCTION AND DEFINITIONS Many chemical reactions take place in aqueous (water) solution. Quantities of such solutions are measured as volumes, while the amounts
Formulas, 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
1. Read P. 368-375, P. 382-387 & P. 429-436; P. 375 # 1-11 & P. 389 # 1,7,9,12,15; P. 436 #1, 7, 8, 11
SCH3U- R.H.KING ACADEMY SOLUTION & ACID/BASE WORKSHEET Name: The importance of water - MAKING CONNECTION READING 1. Read P. 368-375, P. 382-387 & P. 429-436; P. 375 # 1-11 & P. 389 # 1,7,9,12,15; P. 436
neutrons are present?
AP Chem Summer Assignment Worksheet #1 Atomic Structure 1. a) For the ion 39 K +, state how many electrons, how many protons, and how many 19 neutrons are present? b) Which of these particles has the smallest
Chemical Equations & Stoichiometry
Chemical Equations & Stoichiometry Chapter Goals Balance equations for simple chemical reactions. Perform stoichiometry calculations using balanced chemical equations. Understand the meaning of the term
Chemical Calculations
Moles and Molecules Moles and Chemical Reactions Moles, Chemical Reactions, and Molarity All done as UNIT CONVERSIONS!!! and practice, practice, practice CHM 1010 Sinex 1 Mass moles particles conversions
SCH 4C1 Unit 2 Problem Set Questions taken from Frank Mustoe et all, "Chemistry 11", McGraw-Hill Ryerson, 2001
SCH 4C1 Unit 2 Problem Set Questions taken from Frank Mustoe et all, "Chemistry 11", McGraw-Hill Ryerson, 2001 1. A small pin contains 0.0178 mol of iron. How many atoms of iron are in the pin? 2. A sample
Chapter 3 Mass Relationships in Chemical Reactions
Chapter 3 Mass Relationships in Chemical Reactions Student: 1. An atom of bromine has a mass about four times greater than that of an atom of neon. Which choice makes the correct comparison of the relative
Moles. Moles. Moles. Moles. Balancing Eqns. Balancing. Balancing Eqns. Symbols Yields or Produces. Like a recipe:
Like a recipe: Balancing Eqns Reactants Products 2H 2 (g) + O 2 (g) 2H 2 O(l) coefficients subscripts Balancing Eqns Balancing Symbols (s) (l) (aq) (g) or Yields or Produces solid liquid (pure liquid)
Balance the following equation: KClO 3 + C 12 H 22 O 11 KCl + CO 2 + H 2 O
Balance the following equation: KClO 3 + C 12 H 22 O 11 KCl + CO 2 + H 2 O Ans: 8 KClO 3 + C 12 H 22 O 11 8 KCl + 12 CO 2 + 11 H 2 O 3.2 Chemical Symbols at Different levels Chemical symbols represent
Unit 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?
The Mole and Molar Mass
The Mole and Molar Mass 1 Molar mass is the mass of one mole of a substance. Molar mass is numerically equal to atomic mass, molecular mass, or formula mass. However the units of molar mass are g/mol.
TOPIC 7. CHEMICAL CALCULATIONS I - atomic and formula weights.
TOPIC 7. CHEMICAL CALCULATIONS I - atomic and formula weights. Atomic structure revisited. In Topic 2, atoms were described as ranging from the simplest atom, H, containing a single proton and usually
Concept 1. The meaning and usefulness of the mole. The mole (or mol) represents a certain number of objects.
Chapter 3. Stoichiometry: Mole-Mass Relationships in Chemical Reactions Concept 1. The meaning and usefulness of the mole The mole (or mol) represents a certain number of objects. SI def.: the amount of
@ Oxford Fajar Sdn. Bhd. (008974-T) 2012. Matter. 1.1 Atoms and Molecules 1.2 Mole Concept 1.3 Stoichiometry
1 Matter 1.1 Atoms and Molecules 1.2 Mole Concept 1.3 Stoichiometry 2 Chemistry for Matriculation Semester 1 1.1 Atoms and Molecules LEARNING OUTCOMES Describe proton, electron and neutron in terms of
Moles Lab mole. 1 mole = 6.02 x 1023. This is also known as Avagadro's number Demo amu amu amu
Moles I. Lab: Rice Counting II. Counting atoms and molecules I. When doing reactions chemists need to count atoms and molecules. The problem of actually counting individual atoms and molecules comes from
Mole 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
F321 MOLES. Example If 1 atom has a mass of 1.241 x 10-23 g 1 mole of atoms will have a mass of 1.241 x 10-23 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.
The 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
Stoichiometry. 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
Moles, Molecules, and Grams Worksheet Answer Key
Moles, Molecules, and Grams Worksheet Answer Key 1) How many are there in 24 grams of FeF 3? 1.28 x 10 23 2) How many are there in 450 grams of Na 2 SO 4? 1.91 x 10 24 3) How many grams are there in 2.3
APPENDIX B: EXERCISES
BUILDING CHEMISTRY LABORATORY SESSIONS APPENDIX B: EXERCISES Molecular mass, the mole, and mass percent Relative atomic and molecular mass Relative atomic mass (A r ) is a constant that expresses the ratio
IB Chemistry 1 Mole. One atom of C-12 has a mass of 12 amu. One mole of C-12 has a mass of 12 g. Grams we can use more easily.
The Mole Atomic mass units and atoms are not convenient units to work with. The concept of the mole was invented. This was the number of atoms of carbon-12 that were needed to make 12 g of carbon. 1 mole
Atomic Masses. Chapter 3. Stoichiometry. Chemical Stoichiometry. Mass and Moles of a Substance. Average Atomic Mass
Atomic Masses Chapter 3 Stoichiometry 1 atomic mass unit (amu) = 1/12 of the mass of a 12 C atom so one 12 C atom has a mass of 12 amu (exact number). From mass spectrometry: 13 C/ 12 C = 1.0836129 amu
CP Chemistry Review for Stoichiometry Test
CP Chemistry Review for Stoichiometry Test Stoichiometry Problems (one given reactant): 1. Make sure you have a balanced chemical equation 2. Convert to moles of the known substance. (Use the periodic
Moles. Balanced chemical equations Molar ratios Mass Composition Empirical and Molecular Mass Predicting Quantities Equations
Moles Balanced chemical equations Molar ratios Mass Composition Empirical and Molecular Mass Predicting Quantities Equations Micro World atoms & molecules Macro World grams Atomic mass is the mass of an
The Empirical Formula of a Compound
The Empirical Formula of a Compound Lab #5 Introduction A look at the mass relationships in chemistry reveals little order or sense. The ratio of the masses of the elements in a compound, while constant,
2. The percent yield is the maximum amount of product that can be produced from the given amount of limiting reactant.
UNIT 6 stoichiometry practice test True/False Indicate whether the statement is true or false. moles F 1. The mole ratio is a comparison of how many grams of one substance are required to participate in
Topic 4 National Chemistry Summary Notes. Formulae, Equations, Balancing Equations and The Mole
Topic 4 National Chemistry Summary Notes Formulae, Equations, Balancing Equations and The Mole LI 1 The chemical formula of a covalent molecular compound tells us the number of atoms of each element present
Unit 10A Stoichiometry Notes
Unit 10A Stoichiometry Notes Stoichiometry is a big word for a process that chemist s use to calculate amounts in reactions. It makes use of the coefficient ratio set up by balanced reaction equations
PART I: MULTIPLE CHOICE (30 multiple choice questions. Each multiple choice question is worth 2 points)
CHEMISTRY 123-07 Midterm #1 Answer key October 14, 2010 Statistics: Average: 74 p (74%); Highest: 97 p (95%); Lowest: 33 p (33%) Number of students performing at or above average: 67 (57%) Number of students
CHAPTER 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
Part 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
Chemical 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
HOMEWORK 4A. Definitions. Oxidation-Reduction Reactions. Questions
HOMEWORK 4A Oxidation-Reduction Reactions 1. Indicate whether a reaction will occur or not in each of following. Wtiring a balcnced equation is not necessary. (a) Magnesium metal is added to hydrochloric
Ch. 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
SYMBOLS, FORMULAS AND MOLAR MASSES
SYMBOLS, FORMULAS AND MOLAR MASSES OBJECTIVES 1. To correctly write and interpret chemical formulas 2. To calculate molecular weights from chemical formulas 3. To calculate moles from grams using chemical
Chemical 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
Chemical Reactions in Water Ron Robertson
Chemical Reactions in Water Ron Robertson r2 f:\files\courses\1110-20\2010 possible slides for web\waterchemtrans.doc Properties of Compounds in Water Electrolytes and nonelectrolytes Water soluble compounds
How 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
Stoichiometry. 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
Lecture Topics Atomic weight, Mole, Molecular Mass, Derivation of Formulas, Percent Composition
Mole Calculations Chemical Equations and Stoichiometry Lecture Topics Atomic weight, Mole, Molecular Mass, Derivation of Formulas, Percent Composition Chemical Equations and Problems Based on Miscellaneous
Calculating 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
Chapter 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
Name: Class: Date: 2 4 (aq)
Name: Class: Date: Unit 4 Practice Test Multiple Choice Identify the choice that best completes the statement or answers the question. 1) The balanced molecular equation for complete neutralization of
Chapter 5, Calculations and the Chemical Equation
1. How many iron atoms are present in one mole of iron? Ans. 6.02 1023 atoms 2. How many grams of sulfur are found in 0.150 mol of sulfur? [Use atomic weight: S, 32.06 amu] Ans. 4.81 g 3. How many moles
Atomic mass is the mass of an atom in atomic mass units (amu)
Micro World atoms & molecules Laboratory scale measurements Atomic mass is the mass of an atom in atomic mass units (amu) By definition: 1 atom 12 C weighs 12 amu On this scale 1 H = 1.008 amu 16 O = 16.00
Description 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
Matter. Atomic weight, Molecular weight and Mole
Matter Atomic weight, Molecular weight and Mole Atomic Mass Unit Chemists of the nineteenth century realized that, in order to measure the mass of an atomic particle, it was useless to use the standard
Balancing chemical equations
Balancing chemical equations The law of conservation of mass In order to balance a chemical equation, it is important to understand the law of conservation of mass. Definition 1: The law of conservation
Chapter 6 Notes Science 10 Name:
6.1 Types of Chemical Reactions a) Synthesis (A + B AB) Synthesis reactions are also known as reactions. When this occurs two or more reactants (usually elements) join to form a. A + B AB, where A and
Tutorial 4 SOLUTION STOICHIOMETRY. Solution stoichiometry calculations involve chemical reactions taking place in solution.
T-27 Tutorial 4 SOLUTION STOICHIOMETRY Solution stoichiometry calculations involve chemical reactions taking place in solution. Of the various methods of expressing solution concentration the most convenient
Molar Mass Worksheet Answer Key
Molar Mass Worksheet Answer Key Calculate the molar masses of the following chemicals: 1) Cl 2 71 g/mol 2) KOH 56.1 g/mol 3) BeCl 2 80 g/mol 4) FeCl 3 162.3 g/mol 5) BF 3 67.8 g/mol 6) CCl 2 F 2 121 g/mol
Amount of Substance. http://www.avogadro.co.uk/definitions/elemcompmix.htm
Page 1 of 14 Amount of Substance Key terms in this chapter are: Element Compound Mixture Atom Molecule Ion Relative Atomic Mass Avogadro constant Mole Isotope Relative Isotopic Mass Relative Molecular
Ch. 6 Chemical Composition and Stoichiometry
Ch. 6 Chemical Composition and Stoichiometry The Mole Concept [6.2, 6.3] Conversions between g mol atoms [6.3, 6.4, 6.5] Mass Percent [6.6, 6.7] Empirical and Molecular Formula [6.8, 6.9] Bring your calculators!
11-1 Stoichiometry. Represents
11-1 Stoichiometry What is stoichiometry? Calculations that relate the quantities of substances. It is the study of quantitative (measurable amounts) relationships in chemical reactions and equations.
1. What is the molecular formula of a compound with the empirical formula PO and a gram-molecular mass of 284 grams?
Name: Tuesday, May 20, 2008 1. What is the molecular formula of a compound with the empirical formula PO and a gram-molecular mass of 284 grams? 2 5 1. P2O 5 3. P10O4 2. P5O 2 4. P4O10 2. Which substance
The Mole Notes. There are many ways to or measure things. In Chemistry we also have special ways to count and measure things, one of which is the.
The Mole Notes I. Introduction There are many ways to or measure things. In Chemistry we also have special ways to count and measure things, one of which is the. A. The Mole (mol) Recall that atoms of
Stoichiometry. 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 catbon-12
Periodic Table, Valency and Formula
Periodic Table, Valency and Formula Origins of the Periodic Table Mendelѐѐv in 1869 proposed that a relationship existed between the chemical properties of elements and their atomic masses. He noticed
= 11.0 g (assuming 100 washers is exact).
CHAPTER 8 1. 100 washers 0.110 g 1 washer 100. g 1 washer 0.110 g = 11.0 g (assuming 100 washers is exact). = 909 washers 2. The empirical formula is CFH from the structure given. The empirical formula
Solution a homogeneous mixture = A solvent + solute(s) Aqueous solution water is the solvent
Solution a homogeneous mixture = A solvent + solute(s) Aqueous solution water is the solvent Water a polar solvent: dissolves most ionic compounds as well as many molecular compounds Aqueous solution:
Stoichiometry and Aqueous Reactions (Chapter 4)
Stoichiometry and Aqueous Reactions (Chapter 4) Chemical Equations 1. Balancing Chemical Equations (from Chapter 3) Adjust coefficients to get equal numbers of each kind of element on both sides of arrow.
Chapter 6 Chemical Calculations
Chapter 6 Chemical Calculations 1 Submicroscopic Macroscopic 2 Chapter Outline 1. Formula Masses (Ch 6.1) 2. Percent Composition (supplemental material) 3. The Mole & Avogadro s Number (Ch 6.2) 4. Molar