Balancing Equations. Balancing a chemical equation refers to the skill (or art) of

Size: px
Start display at page:

Download "Balancing Equations. Balancing a chemical equation refers to the skill (or art) of"

Transcription

1 Balancing Equations Balancing a chemical equation refers to the skill (or art) of making sure that all atoms that are written on the left of a chemical reaction as reactants are also present on the right side of the equation as products. Since many of the problems you will see in this class require you to start with a balanced chemical equation, this is a skill you must learn now and will use over and over of the course of the year.

2 Balancing Equations Balancing a chemical equation isn t that hard to do, it is a simple trial-and-errorand process that is repeated for each element in the equation until all elements are balanced. After you get the hang of it it can even be kind of fun as you figure out a way to puzzle through h your problem.

3 Balancing Equations Example 1. Balance the following chemical equation: FeCl 3 (aq) + AgNO 3 (aq) = AgCl(s) + Fe(NO 3 ) 3 (aq) The (aq) and the (s) refer to the physical form of the chemical and we will talk about that t more in chapter 4, for now the physical descriptors can be ignored. To balance the equation the only change you can make is to change the coefficient in front of a molecule. You cannot change any of the subscripts in a molecule because that changes the chemical to a different substance.

4 ?FeCl 3 3( (aq) +? AgNO 3 3( (aq) =?AgCl(s) +? Fe(NO 3 3) 3 (aq) So pick an element and make sure you have the same number of atoms of that element on both sides of the equation. For instance, let s start with the iron (Fe). How many Fe s are there on each side of the equation? One Fe both sides of the equations so it is already balanced! That means the coefficients for FeCl 3 and Fe(NO 3 ) 3 can be set to 1.

5 1 FeCl 3 3( (aq) +? AgNO 3 3( (aq) =?AgCl(s) + 1 Fe(NO 3 3) 3 (aq) So pick an element and make sure you have the same number of atoms of that element on both sides of the equation. For instance, let s start with the iron (Fe). How many Fe s are there on each side of the equation? One Fe both sides of the equations so it is already balanced! That means the coefficients for FeCl 3 and Fe(NO 3 ) 3 can be set to 1.

6 1 FeCl 3 3( (aq) +? AgNO 3 3( (aq) =?AgCl(s) + 1 Fe(NO 3 3) 3 (aq) Cl Now let s try the Cl. (Notice I will continue with the table that I started on the last page) 3 Cl s on the left, 1 Cl on the right. So we need to multiply the AgCl on the right hand side by a py g g y coefficient of 3 to get 3 Cl s on this side.

7 1 FeCl 3 3( (aq) +? AgNO 3 3( (aq) =?AgCl(s) + 1 Fe(NO 3 3) 3 (aq) Cl 3 0 3(1) 0 Now let s try the Cl. (Notice I will continue with the table that I started on the last page) 3 Cl s on the left, 1 Cl on the right. So we need to multiply pythe AgCl on the right hand side by a coefficient of 3 to get 3 Cl s on this side. And this sets the coefficient i of AgCl to 3

8 1 FeCl 3 3( (aq) +? AgNO 3 3( (aq) = 3 AgCl(s) + 1 Fe(NO 3 3) 3 (aq) Cl 3 0 3(1) 0 Now let s try the Cl. (Notice I will continue with the table that I started on the last page) 3 Cl s on the left, 1 Cl on the right. So we need to multiply pythe AgCl on the right hand side by a coefficient of 3 to get 3 Cl s on this side. And this sets the coefficient i of AgCl to 3

9 1 FeCl 3 3( (aq) +? AgNO 3 3( (aq) = 3 AgCl(s) + 1 Fe(NO 3 3) 3 (aq) Cl 3 0 3(1) 0 Ag 0 1 3(1) 0 Now let s try the Ag s One on the left, three on the right, we will need to multiply The AgNO 3 by three to make it all balance.

10 1 FeCl 3 3( (aq) + 3 AgNO 3 3( (aq) = 3 AgCl(s) + 1 Fe(NO 3 3) 3 (aq) Cl 3 0 3(1) 0 Ag 0 3(1) 3(1) 0 N O Now let s try the N s The N s look good, I didn t have to mess with any coefficients, so let s finish with the Os O s The O s are balanced as well, so we must be done. The final balanced equation is: 1 FeCl 3 (aq) + 3 AgNO 3 (aq) = 3 AgCl(s) + 1 Fe(NO 3 ) 3 (aq)

11 Balancing equations As you balance a reactant and a product that both contain a given element in an equation, you try not to have to change the coefficient on either of those two compounds again. If you do, then you have to go back and start over. Notice how this worked in the last example.

12 Balancing equations Step 1 FeCl 3 (aq) +AgNO 3 (aq) = AgCl(s) + Fe(NO 3 ) 3 (aq) N t t t ith ith F Cl F (NO ) f Now you try not to mess with either FeCl 3 or Fe(NO 3 ) 3 from this point onward. I will underline them remind myself to try not to touch these coefficients again.

13 Balancing equations Step 2 FeCl 3 (aq) +AgNO 3 (aq) = 3AgCl(s) + Fe(NO 3 ) 3 (aq) Cl 3 0 3(1) 0 Now with the Cl, the AgCl coefficient is fixed, so I will underline that one as well.

14 Balancing equations Step 3 FeCl 3 (aq) + 3AgNO 3 (aq) = 3AgCl(s) + Fe(NO 3 ) 3 (aq) Cl 3 0 3(1) 0 Ag 0 3(1) 3 0 Now with the Ag, the AgNO 3 coefficient is fixed, so I will 3 underline that one as well.

15 Balancing equations Steps 4 and 5 FeCl 3 3( (aq) + 3AgNO 3 3( (aq) = 3AgCl(s) + Fe(NO 3 3) 3 (aq) Cl 3 0 3(1) 0 Ag 0 (3)1 0 3 N O And fixing the Ag fixes the coefficient of the last compound, so we cross our fingers that the N and O will come into balance without and further changes.

16 Balancing Equations Now try this one: Au 2S 3 3( (s) + H 2 2(g) = Au(s) + H 2 S(g)

17 ? Au 2 S 3 (s) +? H 2 (g) =? Au(s) +? H 2 S(g) Au Au first. So you have 1 Au 2 S 3 on the left for a total of 2 Au s, that means you need 2 Au(s) on the right.

18 1 Au 2 S 3 (s) +? H 2 (g) = 2 Au(s) +? H 2 S(g) Au 1(2) 0 2(1) 0 S S next. So if you have 1 Au 2 S 3 on the left, you ll need 3 H 2 S on the right.

19 1 Au 2 S 3 (s) +? H 2 (g) = 2 Au(s) + 3 H 2 S(g) Au 1(2) 0 2(1) 0 S 1(3) 0 0 3(1) H (2) H next. So if you have 3 H 2 S on the left you ll need 3 H 2 s on the right.

20 1 Au 2 S 3 (s) + 3 H 2 (g) = 2 Au(s) + 3 H 2 S(g) Au 1(2) 0 2(1) 0 S 1(3) 0 0 3(1) H 0 3(2) 0 3(2) And it all worked, your final answer is: 1A Au 2 S 3 (s) + 3 H 2 (g) = 2A Au(s) + 3H 2 S(g) These were a couple of nice, easy examples. Now look at the next tutorial for some harder problems.

YIELD YIELD REACTANTS PRODUCTS

YIELD YIELD REACTANTS PRODUCTS Balancing Chemical Equations A Chemical Equation: is a representation of a chemical reaction in terms of chemical formulas Example: 1. Word Description of a Chemical Reaction When methane gas (CH 4 ) burns

More information

Steps for balancing a chemical equation

Steps for balancing a chemical equation The Chemical Equation: A Chemical Recipe Dr. Gergens - SD Mesa College A. Learn the meaning of these arrows. B. The chemical equation is the shorthand notation for a chemical reaction. A chemical equation

More information

NET IONIC EQUATIONS. A balanced chemical equation can describe all chemical reactions, an example of such an equation is:

NET IONIC EQUATIONS. A balanced chemical equation can describe all chemical reactions, an example of such an equation is: NET IONIC EQUATIONS A balanced chemical equation can describe all chemical reactions, an example of such an equation is: NaCl + AgNO 3 AgCl + NaNO 3 In this case, the simple formulas of the various reactants

More information

7-5.5. Translate chemical symbols and the chemical formulas of common substances to show the component parts of the substances including:

7-5.5. Translate chemical symbols and the chemical formulas of common substances to show the component parts of the substances including: 7-5.5 Translate chemical symbols and the chemical formulas of common substances to show the component parts of the substances including: NaCl [salt], H 2 O [water], C 6 H 12 O 6 [simple sugar], O 2 [oxygen

More information

Word Equations and Balancing Equations. Video Notes

Word Equations and Balancing Equations. Video Notes Word Equations and Balancing Equations Video Notes In this lesson, you will: Use the law of conservation of mass and provide standard rules for writing and balancing equations. Write and balance equations

More information

Answers and Solutions to Text Problems

Answers and Solutions to Text Problems Chapter 7 Answers and Solutions 7 Answers and Solutions to Text Problems 7.1 A mole is the amount of a substance that contains 6.02 x 10 23 items. For example, one mole of water contains 6.02 10 23 molecules

More information

Name: Teacher: Pd. Date:

Name: Teacher: Pd. Date: Name: Teacher: Pd. Date: STAAR Tutorial : Energy and Matter: Elements, Compounds, and Chemical Equations: 6.5C Differentiate between elements and compounds on the most basic level. 8.5F Recognize whether

More information

Chapter 5. Chemical Reactions and Equations. Introduction. Chapter 5 Topics. 5.1 What is a Chemical Reaction

Chapter 5. Chemical Reactions and Equations. Introduction. Chapter 5 Topics. 5.1 What is a Chemical Reaction Introduction Chapter 5 Chemical Reactions and Equations Chemical reactions occur all around us. How do we make sense of these changes? What patterns can we find? 1 2 Copyright The McGraw-Hill Companies,

More information

Balancing Chemical Equations

Balancing Chemical Equations Balancing Chemical Equations A mathematical equation is simply a sentence that states that two expressions are equal. One or both of the expressions will contain a variable whose value must be determined

More information

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 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

More information

The Mole Concept. The Mole. Masses of molecules

The Mole Concept. The Mole. Masses of molecules The Mole Concept Ron Robertson r2 c:\files\courses\1110-20\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

Calculating Atoms, Ions, or Molecules Using Moles

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

More information

Limiting Reagent Worksheet #1

Limiting Reagent Worksheet #1 Limiting Reagent Worksheet #1 1. Given the following reaction: (Balance the equation first!) C 3 H 8 + O 2 -------> CO 2 + H 2 O a) If you start with 14.8 g of C 3 H 8 and 3.44 g of O 2, determine the

More information

Chemistry B11 Chapter 4 Chemical reactions

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

More information

Writing Chemical Equations

Writing Chemical Equations Writing Chemical Equations Chemical equations for solution reactions can be written in three different forms; molecular l equations, complete ionic i equations, and net ionic equations. In class, so far,

More information

Chemical Reactions Practice Test

Chemical Reactions Practice Test Chemical Reactions Practice Test Chapter 2 Name Date Hour _ Multiple Choice Identify the choice that best completes the statement or answers the question. 1. The only sure evidence for a chemical reaction

More information

The 5 Types of Chemical Reactions (Chapter 11) By C B 6 th period

The 5 Types of Chemical Reactions (Chapter 11) By C B 6 th period The 5 Types of Chemical Reactions (Chapter 11) By C B 6 th period 1) Combination Reactions Is also referred to as a synthesis reaction It is a chemical change in which two or more substances react to form

More information

Chapter 6 Chemical Calculations

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

More information

H 2 + O 2 H 2 O. - Note there is not enough hydrogen to react with oxygen - It is necessary to balance equation.

H 2 + O 2 H 2 O. - Note there is not enough hydrogen to react with oxygen - It is necessary to balance equation. CEMICAL REACTIONS 1 ydrogen + Oxygen Water 2 + O 2 2 O reactants product(s) reactant substance before chemical change product substance after chemical change Conservation of Mass During a chemical reaction,

More information

Writing, Balancing and Predicting Products of Chemical Reactions.

Writing, Balancing and Predicting Products of Chemical Reactions. Writing, Balancing and Predicting Products of Chemical Reactions. A chemical equation is a concise shorthand expression which represents the relative amount of reactants and products involved in a chemical

More information

Chapter 5 Chemical Quantities and Reactions. Collection Terms. 5.1 The Mole. A Mole of a Compound. A Mole of Atoms.

Chapter 5 Chemical Quantities and Reactions. Collection Terms. 5.1 The Mole. A Mole of a Compound. A Mole of Atoms. Chapter 5 Chemical Quantities and Reactions 5.1 The Mole Collection Terms A collection term states a specific number of items. 1 dozen donuts = 12 donuts 1 ream of paper = 500 sheets 1 case = 24 cans 1

More information

We 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?

We 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 information

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 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

More information

Chapter 6: Writing and Balancing Chemical Equations. AB A + B. CaCO3 CaO + CO2 A + B C. AB + C AC + B (or AB + C CB + A)

Chapter 6: Writing and Balancing Chemical Equations. AB A + B. CaCO3 CaO + CO2 A + B C. AB + C AC + B (or AB + C CB + A) 78 Chapter 6: Writing and Balancing Chemical Equations. It is convenient to classify chemical reactions into one of several general types. Some of the more common, important, reactions are shown below.

More information

Chemical Calculations: Formula Masses, Moles, and Chemical Equations

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

More information

20.2 Chemical Equations

20.2 Chemical Equations All of the chemical changes you observed in the last Investigation were the result of chemical reactions. A chemical reaction involves a rearrangement of atoms in one or more reactants to form one or more

More information

10 Cl atoms. 10 H2O molecules. 8.3 mol HCN = 8.3 mol N atoms 1 mol HCN. 2 mol H atoms 2.63 mol CH2O = 5.26 mol H atoms 1 mol CH O

10 Cl atoms. 10 H2O molecules. 8.3 mol HCN = 8.3 mol N atoms 1 mol HCN. 2 mol H atoms 2.63 mol CH2O = 5.26 mol H atoms 1 mol CH O Chem 100 Mole conversions and stoichiometry worksheet 1. How many Ag atoms are in.4 mol Ag atoms? 6.0 10 Ag atoms 4.4 mol Ag atoms = 1.46 10 Ag atoms 1 mol Ag atoms. How many Br molecules are in 18. mol

More information

Chemical Equations and Chemical Reactions. Chapter 8.1

Chemical Equations and Chemical Reactions. Chapter 8.1 Chemical Equations and Chemical Reactions Chapter 8.1 Objectives List observations that suggest that a chemical reaction has taken place List the requirements for a correctly written chemical equation.

More information

Writing and Balancing Chemical Equations

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

More information

Chemical Reactions 2 The Chemical Equation

Chemical Reactions 2 The Chemical Equation Chemical Reactions 2 The Chemical Equation INFORMATION Chemical equations are symbolic devices used to represent actual chemical reactions. The left side of the equation, called the reactants, is separated

More information

Chapter 11. Electrochemistry Oxidation and Reduction Reactions. Oxidation-Reduction Reactions. Oxidation-Reduction Reactions

Chapter 11. Electrochemistry Oxidation and Reduction Reactions. Oxidation-Reduction Reactions. Oxidation-Reduction Reactions Oxidation-Reduction Reactions Chapter 11 Electrochemistry Oxidation and Reduction Reactions An oxidation and reduction reaction occurs in both aqueous solutions and in reactions where substances are burned

More information

Tuesday, November 27, 2012 Expectations:

Tuesday, November 27, 2012 Expectations: Tuesday, November 27, 2012 Expectations: Sit in assigned seat Get out Folder, Notebook, Periodic Table Have out: Spiral (notes), Learning Target Log (new) No Backpacks on tables Listen/Pay Attention Learning

More information

Formulas, Equations and Moles

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

More information

Chapter 8: Chemical Equations and Reactions

Chapter 8: Chemical Equations and Reactions Chapter 8: Chemical Equations and Reactions I. Describing Chemical Reactions A. A chemical reaction is the process by which one or more substances are changed into one or more different substances. A chemical

More information

Balancing Chemical Equations Practice

Balancing Chemical Equations Practice Science Objectives Students will describe what reactants and products in a chemical equation mean. Students will explain the difference between coefficients and subscripts in chemical equations. Students

More information

6 Reactions in Aqueous Solutions

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

More information

2. The percent yield is the maximum amount of product that can be produced from the given amount of limiting reactant.

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

More information

Calculations and Chemical Equations. Example: Hydrogen atomic weight = 1.008 amu Carbon atomic weight = 12.001 amu

Calculations and Chemical Equations. Example: Hydrogen atomic weight = 1.008 amu Carbon atomic weight = 12.001 amu Calculations and Chemical Equations Atomic mass: Mass of an atom of an element, expressed in atomic mass units Atomic mass unit (amu): 1.661 x 10-24 g Atomic weight: Average mass of all isotopes of a given

More information

2. DECOMPOSITION REACTION ( A couple have a heated argument and break up )

2. DECOMPOSITION REACTION ( A couple have a heated argument and break up ) TYPES OF CHEMICAL REACTIONS Most reactions can be classified into one of five categories by examining the types of reactants and products involved in the reaction. Knowing the types of reactions can help

More information

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 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

More information

Stoichiometry Review

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

More information

How To Calculate Mass In Chemical Reactions

How To Calculate Mass In Chemical Reactions We have used the mole concept to calculate mass relationships in chemical formulas Molar mass of ethanol (C 2 H 5 OH)? Molar mass = 2 x 12.011 + 6 x 1.008 + 1 x15.999 = 46.069 g/mol Mass percentage of

More information

Balancing chemical equations

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

More information

Chapter 8 - Chemical Equations and Reactions

Chapter 8 - Chemical Equations and Reactions Chapter 8 - Chemical Equations and Reactions 8-1 Describing Chemical Reactions I. Introduction A. Reactants 1. Original substances entering into a chemical rxn B. Products 1. The resulting substances from

More information

Formulae, stoichiometry and the mole concept

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

More information

Chapter 3: Stoichiometry

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

More information

Module Four Balancing Chemical Reactions. Chem 170. Stoichiometric Calculations. Module Four. Balancing Chemical Reactions

Module Four Balancing Chemical Reactions. Chem 170. Stoichiometric Calculations. Module Four. Balancing Chemical Reactions Chem 170 Stoichiometric Calculations Module Four Balancing Chemical Reactions DePauw University Department of Chemistry and Biochemistry Page 1 Introduction to Module Four When making a cheeseburger you

More information

Chapter 3 Stoichiometry

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

More information

English already has many collective nouns for fixed, given numbers of objects. Some of the more common collective nouns are shown in Table 7.1.

English already has many collective nouns for fixed, given numbers of objects. Some of the more common collective nouns are shown in Table 7.1. 96 Chapter 7: Calculations with Chemical Formulas and Chemical Reactions Chemical reactions are written showing a few individual atoms or molecules reacting to form a few atoms or molecules of products.

More information

Honors Chemistry: Unit 6 Test Stoichiometry PRACTICE TEST ANSWER KEY Page 1. A chemical equation. (C-4.4)

Honors Chemistry: Unit 6 Test Stoichiometry PRACTICE TEST ANSWER KEY Page 1. A chemical equation. (C-4.4) Honors Chemistry: Unit 6 Test Stoichiometry PRACTICE TEST ANSWER KEY Page 1 1. 2. 3. 4. 5. 6. Question What is a symbolic representation of a chemical reaction? What 3 things (values) is a mole of a chemical

More information

Chapter 12: Oxidation and Reduction.

Chapter 12: Oxidation and Reduction. 207 Oxidation- reduction (redox) reactions Chapter 12: Oxidation and Reduction. At different times, oxidation and reduction (redox) have had different, but complimentary, definitions. Compare the following

More information

Chem 115 POGIL Worksheet - Week 4 Moles & Stoichiometry

Chem 115 POGIL Worksheet - Week 4 Moles & Stoichiometry Chem 115 POGIL Worksheet - Week 4 Moles & Stoichiometry Why? Chemists are concerned with mass relationships in chemical reactions, usually run on a macroscopic scale (grams, kilograms, etc.). To deal with

More information

Liquid phase. Balance equation Moles A Stoic. coefficient. Aqueous phase

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

More information

Chemical Formulas, Equations, and Reactions Test Pre-AP Write all answers on your answer document.

Chemical Formulas, Equations, and Reactions Test Pre-AP Write all answers on your answer document. Name: Period: Chemical Formulas, Equations, and Reactions Test Pre-AP Write all answers on your answer document. 1. Which of the following is a NOT a physical property of hydrogen? A. It is gas C. It is

More information

CHEM 110: CHAPTER 3: STOICHIOMETRY: CALCULATIONS WITH CHEMICAL FORMULAS AND EQUATIONS

CHEM 110: CHAPTER 3: STOICHIOMETRY: CALCULATIONS WITH CHEMICAL FORMULAS AND EQUATIONS 1 CHEM 110: CHAPTER 3: STOICHIOMETRY: CALCULATIONS WITH CHEMICAL FORMULAS AND EQUATIONS The Chemical Equation A chemical equation concisely shows the initial (reactants) and final (products) results of

More information

Chapter 7: Chemical Reactions

Chapter 7: Chemical Reactions Chapter 7 Page 1 Chapter 7: Chemical Reactions A chemical reaction: a process in which at least one new substance is formed as the result of a chemical change. A + B C + D Reactants Products Evidence that

More information

Balancing Chemical Equations

Balancing Chemical Equations Balancing Chemical Equations Academic Success Center Science Tutoring Area Science Tutoring Area Law of Conservation of Mass Matter cannot be created nor destroyed Therefore the number of each type of

More information

Redox Equations under Basic Conditions

Redox Equations under Basic Conditions Redox Equations under Basic Conditions Basic conditions means that t you have more OH - and very little H + in your solution. In fact, you have so little H + that it can t appear in the equation because

More information

Experiment 5. Chemical Reactions A + X AX AX A + X A + BX AX + B AZ + BX AX + BZ

Experiment 5. Chemical Reactions A + X AX AX A + X A + BX AX + B AZ + BX AX + BZ Experiment 5 Chemical Reactions OBJECTIVES 1. To observe the various criteria that are used to indicate that a chemical reaction has occurred. 2. To convert word equations into balanced inorganic chemical

More information

Exam 2 Chemistry 65 Summer 2015. Score:

Exam 2 Chemistry 65 Summer 2015. Score: Name: Exam 2 Chemistry 65 Summer 2015 Score: Instructions: Clearly circle the one best answer 1. Valence electrons are electrons located A) in the outermost energy level of an atom. B) in the nucleus of

More information

EXPERIMENT 7 Reaction Stoichiometry and Percent Yield

EXPERIMENT 7 Reaction Stoichiometry and Percent Yield EXPERIMENT 7 Reaction Stoichiometry and Percent Yield INTRODUCTION Stoichiometry calculations are about calculating the amounts of substances that react and form in a chemical reaction. The word stoichiometry

More information

Chapter 5, Calculations and the Chemical Equation

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

More information

Ch 20 Electrochemistry: the study of the relationships between electricity and chemical reactions.

Ch 20 Electrochemistry: the study of the relationships between electricity and chemical reactions. Ch 20 Electrochemistry: the study of the relationships between electricity and chemical reactions. In electrochemical reactions, electrons are transferred from one species to another. Learning goals and

More information

Chemistry 12 Tutorial 10 Ksp Calculations

Chemistry 12 Tutorial 10 Ksp Calculations Chemistry 12 Tutorial 10 Ksp Calculations Welcome back to the world of calculations. In Tutorial 10 you will be shown: 1. What is meant by Ksp. 2. How to write a "Ksp expression" from a net ionic equation.

More information

Reduction. The gain of electron(s), causing the oxidation number of a species to

Reduction. The gain of electron(s), causing the oxidation number of a species to Reactions Word Coefficient Decomposition Double replacement Law of conservation of charge Law of conservation of energy Law of conservation of mass Mole ratio Oxidation Precipitate Product Reactant Reaction

More information

Other Stoich Calculations A. mole mass (mass mole) calculations. GIVEN mol A x CE mol B. PT g A CE mol A MOLE MASS :

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

More information

Common Ion Effects. CH 3 CO 2 (aq) + Na + (aq)

Common Ion Effects. CH 3 CO 2 (aq) + Na + (aq) Common Ion Effects If two reactions both involve the same ion, then one reaction can effect the equilibrium position of the other reaction. The ion that appears in both reactions is the common ion. Buffers

More information

Redox and Electrochemistry

Redox and Electrochemistry Name: Thursday, May 08, 2008 Redox and Electrochemistry 1. A diagram of a chemical cell and an equation are shown below. When the switch is closed, electrons will flow from 1. the Pb(s) to the Cu(s) 2+

More information

Sample Exercise 3.1 Interpreting and Balancing Chemical Equations

Sample Exercise 3.1 Interpreting and Balancing Chemical Equations Sample Exercise 3.1 Interpreting and Balancing Chemical Equations The following diagram represents a chemical reaction in which the red spheres are oxygen atoms and the blue spheres are nitrogen atoms.

More information

Summer 2003 CHEMISTRY 115 EXAM 3(A)

Summer 2003 CHEMISTRY 115 EXAM 3(A) Summer 2003 CHEMISTRY 115 EXAM 3(A) 1. In which of the following solutions would you expect AgCl to have the lowest solubility? A. 0.02 M BaCl 2 B. pure water C. 0.02 M NaCl D. 0.02 M KCl 2. Calculate

More information

Matter. Atomic weight, Molecular weight and Mole

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

More information

Balancing Chemical Equations

Balancing Chemical Equations Why? Balancing Chemical Equations Atoms are neither created nor destroyed in a chemical reaction, they are just rearranged. In other words, in a chemical reaction, what goes into the reaction must come

More information

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 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

More information

Chapter 3. Chemical Reactions and Reaction Stoichiometry. Lecture Presentation. James F. Kirby Quinnipiac University Hamden, CT

Chapter 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 information

SYMBOLS, FORMULAS AND MOLAR MASSES

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

More information

Introduction to Chemistry

Introduction to Chemistry 1 Copyright ç 1996 Richard Hochstim. All rights reserved. Terms of use. Introduction to Chemistry In Chemistry the word weight is commonly used in place of the more proper term mass. 1.1 Atoms, Ions, and

More information

CHEMICAL REACTIONS. Chemistry 51 Chapter 6

CHEMICAL REACTIONS. Chemistry 51 Chapter 6 CHEMICAL REACTIONS A chemical reaction is a rearrangement of atoms in which some of the original bonds are broken and new bonds are formed to give different chemical structures. In a chemical reaction,

More information

Bomb Calorimetry. Example 4. Energy and Enthalpy

Bomb Calorimetry. Example 4. Energy and Enthalpy Bomb Calorimetry constant volume often used for combustion reactions heat released by reaction is absorbed by calorimeter contents need heat capacity of calorimeter q cal = q rxn = q bomb + q water Example

More information

Chemical Equations & Stoichiometry

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

More information

Name Date Class STOICHIOMETRY. SECTION 12.1 THE ARITHMETIC OF EQUATIONS (pages 353 358)

Name Date Class STOICHIOMETRY. SECTION 12.1 THE ARITHMETIC OF EQUATIONS (pages 353 358) Name Date Class 1 STOICHIOMETRY SECTION 1.1 THE ARITHMETIC OF EQUATIONS (pages 353 358) This section explains how to calculate the amount of reactants required or product formed in a nonchemical process.

More information

Unit 10A Stoichiometry Notes

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

More information

CHEMICAL FORMULAS AND EQUATIONS

CHEMICAL FORMULAS AND EQUATIONS reflect Imagine that you and three other classmates had enough supplies and the recipe to make one pepperoni pizza. The recipe might include a ball of dough, a cup of pizza sauce, a cup of cheese, and

More information

OXIDATION REDUCTION. Section I. Cl 2 + 2e. 2. The oxidation number of group II A is always (+) 2.

OXIDATION REDUCTION. Section I. Cl 2 + 2e. 2. The oxidation number of group II A is always (+) 2. OXIDATION REDUCTION Section I Example 1: Na Example 2: 2C1 Example 3: K + + e Na + + e Cl 2 + 2e K Example 4: C1 2 + 2e 2Cl 1. The oxidation number of group I A is always (+) 1. 2. The oxidation number

More information

Experiment 8 - Double Displacement Reactions

Experiment 8 - Double Displacement Reactions Experiment 8 - Double Displacement Reactions A double displacement reaction involves two ionic compounds that are dissolved in water. In a double displacement reaction, it appears as though the ions are

More information

Aqueous Solutions. Water is the dissolving medium, or solvent. Some Properties of Water. A Solute. Types of Chemical Reactions.

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

More information

CLASS TEST GRADE 11. PHYSICAL SCIENCES: CHEMISTRY Test 6: Chemical change

CLASS TEST GRADE 11. PHYSICAL SCIENCES: CHEMISTRY Test 6: Chemical change CLASS TEST GRADE PHYSICAL SCIENCES: CHEMISTRY Test 6: Chemical change MARKS: 45 TIME: hour INSTRUCTIONS AND INFORMATION. Answer ALL the questions. 2. You may use non-programmable calculators. 3. You may

More information

Unit 7 Stoichiometry. Chapter 12

Unit 7 Stoichiometry. Chapter 12 Unit 7 Stoichiometry Chapter 12 Objectives 7.1 use stoichiometry to determine the amount of substance in a reaction 7.2 determine the limiting reactant of a reaction 7.3 determine the percent yield of

More information

Chemistry Themed. Types of Reactions

Chemistry Themed. Types of Reactions Chemistry Themed Types of Reactions 1 2 Chemistry in the Community-2015-2016 Types of Reactions Date In-Class Assignment Homework T 10/20 TEST on Reactivity of Metals and Redox None W 10/21 Late Start

More information

UNIT (4) CALCULATIONS AND CHEMICAL REACTIONS

UNIT (4) CALCULATIONS AND CHEMICAL REACTIONS UNIT (4) CALCULATIONS AND CHEMICAL REACTIONS 4.1 Formula Masses Recall that the decimal number written under the symbol of the element in the periodic table is the atomic mass of the element. 1 7 8 12

More information

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

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

More information

1332 CHAPTER 18 Sample Questions

1332 CHAPTER 18 Sample Questions 1332 CHAPTER 18 Sample Questions Couple E 0 Couple E 0 Br 2 (l) + 2e 2Br (aq) +1.06 V AuCl 4 + 3e Au + 4Cl +1.00 V Ag + + e Ag +0.80 V Hg 2+ 2 + 2e 2 Hg +0.79 V Fe 3+ (aq) + e Fe 2+ (aq) +0.77 V Cu 2+

More information

1. Thermite reaction 2. Enthalpy of reaction, H 3. Heating/cooling curves and changes in state 4. More thermite thermodynamics

1. Thermite reaction 2. Enthalpy of reaction, H 3. Heating/cooling curves and changes in state 4. More thermite thermodynamics Chem 105 Fri 10-23-09 1. Thermite reaction 2. Enthalpy of reaction, H 3. Heating/cooling curves and changes in state 4. More thermite thermodynamics 10/23/2009 1 Please PICK UP your graded EXAM in front.

More information

CP Chemistry Review for Stoichiometry Test

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

More information

stoichiometry = the numerical relationships between chemical amounts in a reaction.

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

More information

MOLARITY = (moles solute) / (vol.solution in liter units)

MOLARITY = (moles solute) / (vol.solution in liter units) CHEM 101/105 Stoichiometry, as applied to Aqueous Solutions containing Ionic Solutes Lect-05 MOLES - a quantity of substance. Quantities of substances can be expressed as masses, as numbers, or as moles.

More information

Balancing Reaction Equations Oxidation State Reduction-oxidation Reactions

Balancing Reaction Equations Oxidation State Reduction-oxidation Reactions Balancing Reaction Equations Oxidation State Reduction-oxidation Reactions OCN 623 Chemical Oceanography Balanced chemical reactions are the math of chemistry They show the relationship between the reactants

More information

Moles. Moles. Moles. Moles. Balancing Eqns. Balancing. Balancing Eqns. Symbols Yields or Produces. Like a recipe:

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)

More information

1. What is the molecular formula of a compound with the empirical formula PO and a gram-molecular mass of 284 grams?

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

More information

Stoichiometry. Unit Outline

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

More information

ATOMS. Multiple Choice Questions

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)

More information