# Chapter 8 Chemical Quantities

Save this PDF as:

Size: px
Start display at page:

## Transcription

1 Chapter 8 Chemical Quantities Introductory Info The atomic masses of the elements on the periodic table are in the units. These measurements are based on the mass of the standard isotope of the element, which has a mass of. All other elements have a mass that is a fraction or multiple of that isotope. Hydrogen has a mass that is 1/12 of the standard isotope so hydrogen has an atomic mass of. Magnesium s mass is approximately twice the standard isotope, giving it a mass of. One atomic mass unit is extremely small being equal to the mass of one atom ( (73) kg), so it is impractical to use this value in normal lab calculations, so another, larger unit is needed. It should be noted that the ratio of masses of atoms is constant: the ratio of one atom of carbon to one atom of magnesium is to _. The ratio of 2 atoms of carbon to 2 atoms of magnesium is _ to _. The ratio of 10 atoms of carbon to 10 atoms of magnesium is _ to _. The ratio of and number of carbon atoms to the same number of magnesium atoms is to _. The common practice in laboratory calculations is to replace the amu value for an element with grams, giving us a gram atomic mass. It has been found experimentally that the gram atomic mass of an element contains atoms. This is known as Avogadro s number and is known as a mole. A mole of an element is the mass in grams of atoms of that element. One atom of carbon has a mass of amu. Therefore 6.02 x atoms of carbon have a mass of grams. One atom of magnesium has a mass of amu. Therefore 6.02 x atoms of magnesium have a mass of grams. When elements combine to form compounds, the particles of that compound are known as if the compound is covalently bonded, or, if the compound is ionically bonded. The mass of one mole of a compound is the gram formula mass (also known as the molar mass) and is the sum of the gram atomic masses of the atoms in the compound. Thus, a mole of water (H 2 O) consists of _ molecules and has a mass of grams 1 mole HCl = molecules = _grams 2 moles H 2 = molecules = atom = _ grams 1 molecule H 2 O 2 = total atoms 1 mole H 2 O 2 = _ atoms H and _ atoms O 1 mole FeCl 3 = moles Fe +3 and moles Cl - 1 mole FeCl 3 = grams Fe +3 and grams Cl - 1 mole FeCl 3 = total ions and moles of ions H. Cannon, C. Clapper and T. Guillot Klein High School

2 Molecular Weight and Moles Find the molar mass or formula mass of each of the following 1. HNO 3 2. Ammonium nitrate 3. Fe 2 O 3 4. Rubidium Sulfite 5. H 3 PO 4 6. Lithium Carbonate 7. K 2 SO 4 8. Magnesium Hydroxide 9. Be 5 As Aluminum Sulfate Find the mass of each of the following expressed in grams mol of HC 2 H 3 O mol of sodium acetate mol of K 2 CrO g of calcium phosphate mol of Ca(ClO 3 ) mol lithium sulfate mol of Ba(NO 3 ) mol of iron (II) nitrate mol of Na 2 Cr 2 O mol copper (II) acetate Find the mass of each of the following, expressed in moles g of CaCO g of arsenic trichloride g of Ni(NO 3 ) g of calcium phosphide g of C 6 H 12 O g of calcium acetate g K 3 PO g of aluminum nitrate g of Bi(OH) g of iron(ii)phosphate Calculate grams for each of the following x atoms of Na x ions on NaOH x10 23 atoms of Ca x ions Na x atoms of S x molecules H 2 O Calculate the mass in grams for each of the following moles Na moles of O moles Ca moles of Al moles Mg moles H 2 8-2

3 moles Cl moles H 2 SO moles CaCO moles KI moles MgCl moles Ca(OH) moles Al 2 O moles Ca(NO 2 ) 2 Calculate the number of moles of each of the following g F g of Zn g Li g Br g Ne g Fe g Ca g SO g NaOH g Na 2 S g MgCO g K 2 SO g ZnO g H 2 O 2 Calculate the number of atoms, molecules or ions for each of the following moles Na atoms g S atoms mole N atoms g Ca atoms g Na atoms moles CO 2 molecules moles K + ions g H 2 O molecules g H 2 S molecules moles Mg +2 ions 8-3

4 Chemical Quantities Exercise #2 Mole/ Gram Problems 1. How many grams are in 7.20 moles of dinitrogen trioxide? 2. Find the number of moles in 922 g of iron(iii)oxide. 3. Calculate the number of grams in 2.4 moles of potassium oxalate. 4. Calculate the number of moles in 450 g of barium silicate. 5. How many moles are in 1206 g of calcium sulfate? g of chromium (III) bromide contains how many moles? 7. Calculate the number of moles in g of ammonium acetate. 8. How many grams are in 4.5 mol of hydrogen phosphate? mol of iron(ii)permanganate has what mass? 10. What mass of sodium carbonate would be equal to 1.24 mol? 11. What is the mass of mol of potassium nitrate? 12. What is the formula mass of strontium chloride? 13. What is the formula mass of sodium carbonate? 14. How many grams of sodium sulfate are in 5.4 moles of sodium sulfate? 15. How many moles are in 560 g of calcium phosphate? 16. How many moles are in 5.6 x 10 3 g of ammonium oxalate? 17. How many g of iron (III)perchlorate are in 625 moles? g of plumbous silicate was used in an experiment. Calculate the number of moles contained in the amount of this substance. 19. If 4.57 moles of ammonium acetate were used to activate a chemical reaction, how many grams were needed? 20. Determine which substance provides the most mass; 3.5 moles of iron(iii) carbide or 3.5 moles of iron (III) oxide 21. Calculate the number of moles contained in 5.6 x 10 5 grams of silver nitrate 22. Determine the number of moles in 450g of potassium dichromate. 23. Which has more mass, 3.5 moles of calcium carbonate or 3.5 moles of calcium phosphate? 24. Which has more moles, 100.0g of sodium hydroxide or g of potassium hydroxide? 25. What mass of water would it take to give you one mole? 8-4

5 Practice Problems For the following determine moles or grams 1. moles in 56g of calcium phosphate 2. grams in 5.6 moles of silver nitrate 3. grams in 6.7 moles of zinc acetate 4. moles in g of ferric sulfide 5. moles in 1.2 x 10 4 g of mercurous nitrate 6. moles in g of potassium oxalate 7. grams in moles of copper (II) sulfate 8. grams in 1.2 x 10-2 moles aluminum silicate 9. grams in moles of mercury (I) bicarbonate 10. moles in 5.6 x 10 4 g of magnesium chlorate Chemical Quantities Exercise #4 For the following calculate the gram formula mass 11. aluminum acetate 12. calcium nitrate 13. nitrogen trioxide 14. mercuric chloride 15. silicon tetraflouride 16. tin (IV) sulfite 17. ammonium hydroxide 18. strontium acetate 19. Calcium hydroxide 20. Hydrogen phosphate For the following calculate number of particles moles of sodium chloride grams of barium chloride moles of silver sulfate grams of aluminum bromide moles of calcium flouride 8-5

6 Exercise #5 Percent Composition 1. What is the percent composition of H in H 2 O? 2. What is the % composition of Al in AlPO 4? 3. What is the % composition of Ca in Ca(OH) 2? 4. What is the % composition of C in Ba(C 2 H 3 O 2 ) 2? 5. What is the % of Pb in PbCl 4? 6. What is the % composition of NH 4 in (NH 4 ) 2 SO 3? 7. What is the % composition of hydrogen in calcium hydroxide? 8. What is the % composition of oxygen in CO 2 9. A 5.2 g piece of magnesium combines with 3.1g of oxygen to form a compound, what is the % composition of magnesium in this compound? 10. A 2.2g piece of sodium combines with 6.3g of iodine to form a compound. What is the % composition of iodine in this compound? 11. A 15.2g piece of sulfur combines with 9.4g of potassium to form a compound. What is the % of potassium in the compound? 12. A 1.5g piece of barium combines with 9.0g of phosphorous to form a compound. What is the % composition of barium in this compound? 13. An 8.20g piece of magnesium combines completely with 5.40g of chlorine to form a compound. What is the % composition of this compound? 14. Calculate the % composition of carbon in calcium acetate. 15. Calculate the percent of sulfur in sodium bisulfate. 16. Which compound contains the most hydrogen; a. 20.0g of potassium hydrogen sulfate b. 124g of calcium acetate c. 378g of hydrogen cyanide 17. If 500g of sodium chloride were analyzed, how many grams of sodium metal would be found? 18. How many grams of hydrogen can be derived from 5.6 x 10 5 g of water? 19. Iron metal can be extracted from iron ore. There are two types of iron ore, iron (III) oxide and iron (II) oxide. If you had 800.0g of each ore, which ore would produce the most iron metal? 20. How many moles in 30.0 cm 3 of copper? (the density of copper is 8.92g/cm 3 ) 8-6

7 Empirical Formula _ 1. What is the empirical formula of a compound containing 63g of Rb and 5.9g of O? _ 2. What is the empirical formula of a compound with 0.159g of U and 0.119g of Cl? _ 3. Write the empirical formula for the compound that has 7.22g of Ni, 2.53g of P, and 5.25g of O. _ 4. If a compound contains 0.285g of Ca, 0.236g of S and 0.469g of O, what is its empirical formula? _ 5. If a compound is made up of 32.8% Cr and 67.2% Cl, what is it s empirical formula? _ 6. What is the empirical formula of a compound found to contain 42.7% Co and 57.3% Se? _ 7. Find the empirical formula of a compound that is 56.6% La and 43.4% Cl. _ 8. What is the empirical formula of a compound that is Ta and 18.1% O? _ 9. If the % composition of a compound is 92.3% C and 7.7% H, what is the empirical formula? _ 10. Find the empirical formula of a compound with a % composition of 26.7% P, 12.2% N and 61.2% Cl. _ 11. A hydrate was analyzed to determine that it contained 5.262g of Tl(NO 3 ) 3 and 0.789g of water, what is the formula of the hydrate? _ 12. What is the formula for a hydrate if it contains 2.94g of Sn(NO 3 ) 2 and 4.37g of water? _ 13. In a chemical reaction, 1.58g of copper combine with sulfur to give 1.98g of a new compound. What is the empirical formula of this new compound? _ 14. An analysis determines that a compound is made of 42.9% carbon and 57.1% oxygen, what is the empirical formula? _ 15. In a chemical process the following data was collected. 44.5% copper and 55.7% bromine. Calculate the correct empirical formula for the compound. _ 16. From the following data determine the correct empirical formula. _ 38.9% Ba, 29.4% Cr and 31.7% O. 17. In a chemical reaction, 0.274g of aluminum combine with iodine to form 4.41g of a new product. What is the empirical formula of this product? _ 18. What is the empirical formula of a compound containing 9.93% carbon, 58.6% chlorine and 31.1% fluorine? 8-7

8 Molecular Formula 1. The molecular formula of a compound is either the same as its empirical formula or a _ of it. 2. What do you need to know to calculate the molecular formula of a compound? 3. If you divide the molecular mass of a compound by the empirical formula mass, what is the result? 4. What would you use to convert the empirical formula of a compound to a molecular formula? 5. Gas X is found to be 24.0% carbon and 76.0% fluorine, what is its empirical formula? Given that the molar mass of gas X is g/mol, determine its molecular formula. 6. Ribose is an important sugar (part of RNA), with a molar mass of g/mol. If its empirical formula is CH 2 O, what is its molecular formula? 7. Naphthalene is a soft covalent solid that is often used in mothballs. Its molar mass is g/mol and it contains 93.75% carbon and 6.25% hydrogen. Determine the molecular formula of naphthalene from this data. 8. What is the molecular formula for a compound with a molecular mass of 30.0 g/mol containing 80.0% hydrogen and 20.0 % oxygen? 9. If a compound contains 37.8% carbon 6.3% hydrogen, 55.8% chlorine and a molecular mass of 127.0g/mol, what is the molecular formula 8-8

9 Chemical Quantities Review 1. What is the molecular mass of dinitrogen pentoxide? 2. Calculate the formula weight of aluminum silicate. 3. What is the % composition of phosphorous in plumbic phosphate? 4. What is the % composition of each element in barium acetate? 5. What is the mass of 3.04 moles of sodium carbonate? 6. How many atoms are there in 84.4g of carbon 7. How many moles are in 481g of magnesium phosphate? 8. What is the mass of 5.94 x formula units of calcium chlorate? 9. A 5.2g piece of magnesium combines with 3.1g of oxygen, what is the % composition of magnesium in the compound? 10. If 15.2g of sulfur combine with 9.4g of potassium, what is the % composition of potassium in the compound? 11. What is the % composition of a compound formed when 6.3g of iodine combine w 2.2g of sodium? 12. What is the empirical formula for a compound that contains 23.6g of sulfur, 46.9g oxygen and 29.5g of calcium? 13. Find the empirical formula for the compound with the following analysis: 8.54g M 16.78g C, 2.1g H, 22.49g O. 14. Find the empirical formula for the compound with the following analysis: 9.93% carbon, 58.6% chlorine, and 31.3% fluorine. 15. What is the empirical formula for a compound that contains 5.03g of aluminum and 8.97g of sulfur? 16. What is the percent composition of magnesium in 3.50 mole of magnesium nitride? 17. A compound is found to contain 33.3% calcium, 40.0% oxygen, and 26.7% sulfur. What is the empirical formula for the compound? 18. What is the molecular formula of a compound with a molecular mass of 78 g/mol if the % composition is 92.3% carbon, and 7.7% hydrogen? 19. A compound is found to have a percent composition of 80.4% bismuth, 18.5% oxygen and 1.16% hydrogen. What is the empirical formula? 8-9

10 Lab #3 Chapter 8 LAB: DETERMINATION OF THE FORMULA OF A HYDRATE OBJECTIVE: Given a sample of hydrated salt and appropriate apparatus, the student will be able to experimentally determine the correct formula for the compound. APPARATUS: goggles, Bunsen burner, matches, crucible, triangle, crucible tongs, ringstand and ring, spatula, balance. PROCEDURE: 1. Weigh a crucible to the nearest 0.01 gram. Add approximately 2 grams of salt. Record total weight of salt and crucible to the nearest 0.01 gram. Subtract to find the weight of your salt. 2. Support the crucible on the triangle at an appropriate height to receive the maximum heat of the flame. WARNING: hydrates, upon heating, can decrepitate (explode). Protect your eyes at all times. Heat the crucible gently at first. Too rapid heating may cause loss by spattering because the water of hydration is driven off too rapidly. Gradually heat more strongly, keeping the crucible in the hottest part of the flame. After ten minutes of strong heating, gradually withdraw the flame, wait a moment, then use the crucible tongs to move the crucible to the base of the ringstand to cool for at least three minutes. Never put a hot crucible on a balance. When cooled enough to touch, move to the balance with crucible tongs, weigh and record. 3. Repeat the heating, cool, and reweigh. Continue this process until you get two successive weighing within 0.20 grams. This is called heating to constant weight. Discard the used, now anhydrous salt in the trash. The crucible may then be washed out with tap water. 4. SHOW ALL CALCULATIONS CLEARLY AND NEATLY. WATCH SIGNIFICANT DIGITS. a. Use the lowest weight to find the mass of anhydrous salt. b. Find the formula mass of your salt. c. Find moles of your salt. d. Subtract the two masses to find the mass of water e. Find moles of water f. Right the formula for the hydrate g. Calculate the percentage of water in the hydrated salt h. Find the formula mass of the hydrated salt. i. Calculate the theoretical percentage of water in the hydrate j. Calculate your percent error. 8-10

### 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

### 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

### Test 3 Formula and math of formula review. 2. The oxide of metal X has the formula XO. Which group in the Periodic Table contains metal X?

Name: Sunday, November 04, 2007 Test 3 Formula and math of formula review 1. Which is an example of a binary compound? 1. acetic acid 3. potassium hydroxide 2. nitric acid 4. potassium oxide 2. The oxide

### CHAPTER 3 COMPOUNDS AND MOLECULES

Chapter 3 Compounds and Molecules Page 1 CHAPTER 3 COMPOUNDS AND MOLECULES 3-1. Octane, a component of gasoline, has eight carbon atoms and eighteen hydrogen atoms per molecule. Its formula is written

### 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

### 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?

### Summer Assignment Coversheet

Summer Assignment Coversheet Course: A.P. Chemistry Teachers Names: Mary Engels Assignment Title: Summer Assignment A Review Assignment Summary/Purpose: To review the Rules for Solubility, Oxidation Numbers,

### Chemical Proportions in Compounds

Chapter 6 Chemical Proportions in Compounds Solutions for Practice Problems Student Textbook page 201 1. Problem A sample of a compound is analyzed and found to contain 0.90 g of calcium and 1.60 g of

### 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

### Monatomic Ions. A. Monatomic Ions In order to determine the charge of monatomic ions, you can use the periodic table as a guide:

Monatomic Ions Ions are atoms that have either lost or gained electrons. While atoms are neutral, ions are charged particles. A loss of electrons results in a positive ion or cation (pronounced cat-eye-on

### b. N 2 H 4 c. aluminum oxalate d. acetic acid e. arsenic PART 2: MOLAR MASS 2. Determine the molar mass for each of the following. a. ZnI 2 b.

CHEMISTRY DISCOVER UNIT 5 LOTS OF PRACTICE ON USING THE MOLE!!! PART 1: ATOMIC MASS, FORMULA MASS, OR MOLECULAR MASS 1. Determine the atomic mass, formula mass, or molecular mass for each of the following

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

### 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

### Balancing Chemical Equations

Balancing Chemical Equations 1. sodium carbonate + calcium hydroxide sodium hydroxide + calcium carbonate Na 2 CO 3 + Ca(OH) 2 2 NaOH + CaCO 3 2. carbon dioxide + water carbonic acid CO 2 + H 2 O H 2 CO

### Decomposition. Composition

Decomposition 1. Solid ammonium carbonate is heated. 2. Solid calcium carbonate is heated. 3. Solid calcium sulfite is heated in a vacuum. Composition 1. Barium oxide is added to distilled water. 2. Phosphorus

### CHEMICAL EQUATIONS and REACTION TYPES

31 CHEMICAL EQUATIONS and REACTION TYPES The purpose of this laboratory exercise is to develop skills in writing and balancing chemical equations. The relevance of this exercise is illustrated by a series

### Chapter 5 - Molecules and Compounds

Chapter 5 - Molecules and Compounds How do we represent molecules? In pictures In formula In name Ionic compounds Molecular compounds On the course website, you will find a list of ions that I would like

### MOLE CONVERSION PROBLEMS. 2. How many moles are present in 34 grams of Cu(OH) 2? [0.35 moles]

MOLE CONVERSION PROBLEMS 1. What is the molar mass of MgO? [40.31 g/mol] 2. How many moles are present in 34 grams of Cu(OH) 2? [0.35 moles] 3. How many moles are present in 2.5 x 10 23 molecules of CH

### 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

### Chapter 8 How to Do Chemical Calculations

Chapter 8 How to Do Chemical Calculations Chemistry is both a qualitative and a quantitative science. In the laboratory, it is important to be able to measure quantities of chemical substances and, as

### Unit 9 Stoichiometry Notes (The Mole Continues)

Unit 9 Stoichiometry Notes (The Mole Continues) 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

### 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

### MOLECULAR 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

### Chapter 3. Stoichiometry: Ratios of Combination. Insert picture from First page of chapter. Copyright McGraw-Hill 2009 1

Chapter 3 Insert picture from First page of chapter Stoichiometry: Ratios of Combination Copyright McGraw-Hill 2009 1 3.1 Molecular and Formula Masses Molecular mass - (molecular weight) The mass in amu

### Programme in mole calculation

Programme in mole calculation Step 1 Start at the very beginning Atoms are very small indeed! If we draw a line 1 metre long, 6,000,000,000 (6 billion) atoms could be lined end to end. So a scientist cannot

### 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

### Formulae, Equations & Formula Mass

St Peter the Apostle High School Chemistry Department Formulae, Equations & Formula Mass N4 & N5 Homework Questions Answer questions as directed by your teacher. National 4 level questions are first followed

### Sample Exercise 2.1 Illustrating the Size of an Atom

Sample Exercise 2.1 Illustrating the Size of an Atom The diameter of a US penny is 19 mm. The diameter of a silver atom, by comparison, is only 2.88 Å. How many silver atoms could be arranged side by side

### Nomenclature of Ionic Compounds

Nomenclature of Ionic Compounds Ionic compounds are composed of ions. An ion is an atom or molecule with an electrical charge. Monatomic ions are formed from single atoms that have gained or lost electrons.

### Chapter 3 Stoichiometry: Calculations with Chemical Formulas and Equations

CHE11 Chapter Chapter Stoichiometry: Calculations with Chemical Formulas and Equations 1. When the following equation is balanced, the coefficients are. NH (g) + O (g) NO (g) + H O (g) (a). 1, 1, 1, 1

### Ionic Compounds and Ionic Bonding

Ionic Compounds and Ionic Bonding 1 Chemical Bonds There are three basic types of bonds: Ionic The electrostatic attraction between ions Covalent The sharing of electrons between atoms Metallic Each metal

### 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

### 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 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

### = 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

### 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

### WRITING CHEMICAL FORMULA

WRITING CHEMICAL FORMULA For ionic compounds, the chemical formula must be worked out. You will no longer have the list of ions in the exam (like at GCSE). Instead you must learn some and work out others.

### Naming Compounds Tutorial and Worksheet

Naming Compounds Tutorial and Worksheet Since we use different methods in naming binary covalent (molecular) compounds and ionic compounds, the first step in naming or writing the formula of a compound

### Naming Compounds Handout

Naming Compounds Handout IONIC COMPOUNDS versus MOLECULAR COMPOUNDS ionic compound: consist of cations (positive ions) and anions (negative ions) held together by electrostatic attraction usually metal

### Chapter 9. Answers to Questions

Chapter 9 Answers to Questions 1. Word equation: Silicon Tetrachloride + Water Silicon Dioxide + Hydrogen Chloride Formulas: Next, the chemical formulas are needed. As these are all covalent compounds,

### 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

### 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

### 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

### 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

### 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

### Determination of an Empirical Formula and % Composition

Chem 110 Lab Clark College Determination of an Empirical Formula and % Composition Percent composition will be discussed in your text, lecture and in lab. This concept is often used to determine how many

### 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

### Problem Solving. Mole Concept

Skills Worksheet Problem Solving Mole Concept Suppose you want to carry out a reaction that requires combining one atom of iron with one atom of sulfur. How much iron should you use? How much sulfur? When

### 0.786 mol carbon dioxide to grams g lithium carbonate to mol

1 2 Convert: 2.54 x 10 22 atoms of Cr to mol 4.32 mol NaCl to grams 0.786 mol carbon dioxide to grams 2.67 g lithium carbonate to mol 1.000 atom of C 12 to grams 3 Convert: 2.54 x 10 22 atoms of Cr to

### Unit 6. Chapter 10: The MOLE! Date In Class Homework. % Composition & Calculating Empirical Formulas

Date In Class Homework 10/22 Thur Counting By Mass Lab 10/23 Fri (mole day!!!) THE MOLE! in room 137 10/26 Mon (LSM) More on the Mole Watch empirical and molecular formula video. 10/27 Tue % Composition

### 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)

### EXPERIMENT 5: CHEMICAL REACTIONS AND EQUATIONS

PURPOSE EXPERIMENT 5: CHEMICAL REACTIONS AND EQUATIONS To perform and observe simple chemical reactions. To identify the products of chemical reactions and write balanced equations for those reactions.

### 9. The molar mass of hydrazine is 32 g/mol and its empirical formula is NH 2. What is its molecular formula?

Dr. Rogers Solutions Homework 1. Give the name for the following compounds and state whether they are ionic or not A. Ba(NO 3 ) 2 B. NaH C. PCl 5 D. CO E. NH 4 OH F. Ca(MnO 4 ) 2 G. N 2 O 4 H. NaHSO 4

### AP Chemistry Pre-Course Packet

AP Chemistry PreCourse Packet AP Chemistry, Fall 2015 Get excited (and ready) for AP Chemistry! Name: Included in this packet is information about the exam and information you should KNOW (memorize or

### Naming Compounds Handout Key

Naming Compounds Handout Key p. 2 Name each of the following monatomic cations: Li + = lithium ion Ag + = silver ion Cd +2 = cadmium ion Cu +2 = copper (II) ion Al +3 = aluminum ion Mg +2 = magnesium ion

### Exercise 3.5 - Naming Binary Covalent Compounds:

Chapter Exercise Key 1 Chapter Exercise Key Exercise.1 Classifying Compounds: Classify each of the following substances as either a molecular compound or an ionic compound. a. formaldehyde, CH 2 O (used

### 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

### 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

### Name: Block: Date: Test Review: Chapter 8 Ionic Bonding

Name: Block: Date: Test Review: Chapter 8 Ionic Bonding Part 1: Fill-in-the-blank. Choose the word from the word bank below. Each word may be used only 1 time. electron dot structure metallic electronegativity

### EXPERIMENT 12: Empirical Formula of a Compound

EXPERIMENT 12: Empirical Formula of a Compound INTRODUCTION Chemical formulas indicate the composition of compounds. A formula that gives only the simplest ratio of the relative number of atoms in a compound

### Nomenclature Packet. 1. Name the following ionic compounds: a. Al 2 O 3 Aluminum oxide. b. Cs 2 O Cesium oxide. c. Rb 3 N Rubidium nitride

Nomenclature Packet Worksheet I: Binary Ionic Compounds (representative metals) metals from groups 1A, 2A, and 3A (1, 2, and 13) have constant charges as ions and do NOT get Roman Numerals in their names

### The Chemistry Name Game

The Chemistry Name Game Contributed by Butane: The Carroll College Chemistry Club Main Science Idea for Kids As students play the Chemistry Name Game, they will learn why compounds form as they do. They

### 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.

### 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

### 19.2 Chemical Formulas

In the previous section, you learned how and why atoms form chemical bonds with one another. You also know that atoms combine in certain ratios with other atoms. These ratios determine the chemical formula

### CHEMICAL FORMULAS AND FORMULA WEIGHT CALCULATIONS

CHEMICAL FORMULAS AND FORMULA WEIGHT CALCULATIONS 1. THE MEANING OF A CHEMICAL FORMULA A chemical formula is a shorthand method of representing the elements in a compound. The formula shows the formulas

### 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

### 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

### 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

### 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.

### General Chemistry I (FC, 09-10) Lab #3: The Empirical Formula of a Compound. Introduction

General Chemistry I (FC, 09-10) 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, does not

### Problem Solving. Percentage Composition

Skills Worksheet Problem Solving Percentage Composition Suppose you are working in an industrial laboratory. Your supervisor gives you a bottle containing a white crystalline compound and asks you to determine

### Percent Composition of a Hydrate

Chem 110 Lab Percent Composition of a Hydrate Clark College Percent composition will be discussed in your text, lecture and in lab. This concept is often used to determine how many grams of an element

### AP Chem Unit 1 Assignment 3 Chemical Equations

Symbols used in chemical equations: Symbol Meaning + used to separate one reactant or product from another used to separate the reactants from the products - it is pronounced "yields" or "produces" when

### Stoichiometry. Lecture Examples Answer Key

Stoichiometry Lecture Examples Answer Key Ex. 1 Balance the following chemical equations: 3 NaBr + 1 H 3 PO 4 3 HBr + 1 Na 3 PO 4 2 C 3 H 5 N 3 O 9 6 CO 2 + 3 N 2 + 5 H 2 O + 9 O 2 2 Ca(OH) 2 + 2 SO 2

### 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,

### The Mole Concept and Atoms

Copyright The McGraw-Hill 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

### 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

### Chemistry 65 Chapter 6 THE MOLE CONCEPT

THE MOLE CONCEPT Chemists find it more convenient to use mass relationships in the laboratory, while chemical reactions depend on the number of atoms present. In order to relate the mass and number of

### Stoichiometry. Unit Outline

3 Stoichiometry Unit Outline 3.1 The Mole and Molar Mass 3.2 Stoichiometry and Compound Formulas 3.3 Stoichiometry and Chemical Reactions 3.4 Stoichiometry and Limiting Reactants 3.5 Chemical Analysis

### 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

### 1. 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

### CHEMICAL NAMES AND FORMULAS

9 CHEMICAL NAMES AND FORMULAS SECTION 9.1 NAMING IONS (pages 253 258) This section explains the use of the periodic table to determine the charge of an ion. It also defines polyatomic ion and gives the

### 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)

### Calculating Molar Mass of a Compound

Instructions for Conversion Problems For every conversion problem Write the number in the problem down with unit and a multiplication sign Decide which conversion factor you should use, Avagadro s or molar

### Chapter 3 Stoichiometry

Chapter 3 Stoichiometry 3-1 Chapter 3 Stoichiometry In This Chapter As you have learned in previous chapters, much of chemistry involves using macroscopic measurements to deduce what happens between atoms

### 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

### CHAPTER 5: MOLECULES AND COMPOUNDS

CHAPTER 5: MOLECULES AND COMPOUNDS Problems: 1-6, 9-13, 16, 20, 31-40, 43-64, 65 (a,b,c,e), 66(a-d,f), 69(a-d,f), 70(a-e), 71-78, 81-82, 87-96 A compound will display the same properties (e.g. melting

### Name 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

### Practice Hour Examination I. Use the Periodic Table in your book. Normally one will be provided. These are some sample problems.

Chemistry 1111 bruary 2011 Practice Hour Examination I Use the Periodic Table in your book. Normally one will be provided. These are some sample problems. 1. What is the average mass (in grams) of one

### 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

### Elements and Compounds. Chemical Bonds compounds are made of atoms held together by chemical bonds bonds are forces of attraction between atoms

Elements and Compounds elements combine together to make an almost limitless number of compounds the properties of the compound are totally different from the constituent elements Tro, Chemistry: A Molecular

### Naming ions and chemical compounds Worksheet #1. a. iodide ion b. barium ion c. mercury(ii) ion. d. Tin(IV) ion e. Phosphide ion f.

Naming ions and chemical compounds Worksheet #1 Write the symbol for each ion. Be sure to include the charge. a. iodide ion b. barium ion c. mercury(ii) ion d. Tin(IV) ion e. Phosphide ion f. Silver ion

### CHAPTER 9. 9.1 Naming Ions. Chemical Names and Formulas. Naming Transition Metals. Ions of Transition Metals. Ions of Transition Metals

CHAPTER 9 Chemical Names and Formulas 9.1 Naming Ions Monatomic Ions: a single atom with a positive or negative charge Cation (rules): listed first Anion (rules): ide ending Transition Metals have a varying

### Chapter 3. Molecules, Compounds, and Chemical Composition

Chapter 3 Molecules, Compounds, and Chemical Composition Elements and Compounds Elements combine together to make an almost limitless number of compounds. The properties of the compound are totally different

### Problem Solving. Empirical Formulas

Skills Worksheet Problem Solving Empirical Formulas Suppose you analyze an unknown compound that is a white powder and find that it is composed of 36.5% sodium, 38.1% oxygen, and 25.4% sulfur. You can

### NAMING QUIZ 3 - Part A Name: 1. Zinc (II) Nitrate. 5. Silver (I) carbonate. 6. Aluminum acetate. 8. Iron (III) hydroxide

NAMING QUIZ 3 - Part A Name: Write the formulas for the following compounds: 1. Zinc (II) Nitrate 2. Manganese (IV) sulfide 3. Barium permanganate 4. Sulfuric acid 5. Silver (I) carbonate 6. Aluminum acetate

### B) atomic number C) both the solid and the liquid phase D) Au C) Sn, Si, C A) metal C) O, S, Se C) In D) tin D) methane D) bismuth B) Group 2 metal

1. The elements on the Periodic Table are arranged in order of increasing A) atomic mass B) atomic number C) molar mass D) oxidation number 2. Which list of elements consists of a metal, a metalloid, and