DETERMINING THE ENTHALPY OF FORMATION OF CaCO 3

Size: px
Start display at page:

Download "DETERMINING THE ENTHALPY OF FORMATION OF CaCO 3"

Transcription

1 DETERMINING THE ENTHALPY OF FORMATION OF CaCO 3 Standard Enthalpy Change Standard Enthalpy Change for a reaction, symbolized as H 0 298, is defined as The enthalpy change when the molar quantities of reactants shown in a balanced chemical equation completely react to from products under standard conditions. Standard conditions are as follows: - a pressure of 1 atmosphere - a temperature of 298 K - if solution is used, 1M is specified. - Elements or compounds in their normal stable state Example H 2(g) + 1/2 O 2(g) H 2 O (l) H 0 = kj mol -1 When one mole of hydrogen and half mole of oxygen react to form one mole water, kj of heat are evolved under standard conditions. This is an exothermic reaction. All the substance involved must be in their normal physical states under standard conditions. The enthalpy of all elements in their most stable form and standard state is conventionally taken as zero. For example, H [O 2(g) ] = 0 H 0 298[Na (s) ]=0 Therefore, the standard enthalpy of formation of a compound represents the enthalpy content of the compound. Hess s Law The law of conservation of energy states that energy can be neither be created or destroyed, though one form of energy can be converted to another form. This law therefore implies that the total energy content ( in the system ) is constant. Based on it, Hess s law arises. Hess s Law: The standard enthalpy change of reaction depends only on the difference between the standard enthalpy of the reactants and the standard enthalpy of the products, and not no the route by which the reaction occurs. In other words, for processes involving several stages, the enthalpy change for the reaction is equal to the algebraic sum of the enthalpy change for each intermediate stage. Page 1

2 The enthalpy change for the oxidation of carbon (graphite) to carbon dioxide is the same whether it is carried out Route A ( 1 stage ) or Route B ( 2 stages) Route A: C (s) + O 2(g) CO 2(g) H a = kj mol -1 Route B: C (s) + 1/2 O 2(g) CO (g) H b1 = kj mol -1 CO (g) + 1/2 O 2(g) CO 2(g) H b2 = kj mol -1 H b1 + H b2 = (-110.5) + (-283.0) = kj mol -1 The Use of Hess s Law in determining Enthalpy Changes Some reactions proceed very slowly or involve formation of side products. Hess s Law can be used to determine the enthalpy changes of such reactions which cannot be determined directly by calorimetry experiments. Page 2

3 The molar enthalpy of formation, H f, is defined as the enthalpy change when 1 mole of a compound is formed directly from its elements. Although some compounds (e.g., MgO) can be formed by direct synthesis from the elements, many cannot. Calcium carbonate is one of them. Below is the chemical equation representing the formation of 1 mole of CaCO 3 :- Ca (s) + C (s) + 1½ O 2 (g) CaCO 3 (s) The enthalpy change for this reaction can be found indirectly from reactions which can actually be carried out in the lab and then applying Hess s Law. Both calcium metal and calcium carbonate react with dilute hydrochloric acid to form a solution of calcium chloride. In addition, calcium metal forms H 2 gas and calcium carbonate forms CO 2 and H 2 O. The enthalpy changes for these two reactions can be measured relatively easily in the lab. For the calculation of H f for CaCO 3, two more pieces of data are needed, i.e., the enthalpies of formation of water and carbon dioxide. Page 3

4 Page 4

5 METHOD 1) H 1 for Ca + HCl Weigh out accurately about 1g of calcium metal into a weighing bottle and record the mass. Weigh a polystyrene calorimeter cup and record the mass. Use a measuring cylinder to add 100cm 3 of 1M HCl. Reweigh the cup with the acid and record the mass. Place the polystyrene cup inside a beaker for support, as shown in the diagram opposite. Place the thermometer in the acid and start the stop-clock. Record the temperature every minute for 3 minutes. On the 4 th minute, quickly add all the calcium metal and stir to mix thoroughly, keeping the lid on top of the cup. Record the temperature every minute from the 5 th minute for a further 10 minutes. Stir the solution before each reading. Empty and rinse the cup and thermometer and dry them with paper towel. 2) H 2 for CaCO 3 + HCl Weigh out accurately between 2 and 3g of calcium carbonate powder into a clean weighing bottle and record the mass. Using the same polystyrene cup as before, add a fresh lot of 100cm 3 of 1M HCl using the measuring cylinder, weigh again and record the mass. Repeat the steps in experiment 1, recording the temperature every minute and adding the solid on the 4 th minute. Empty and rinse the cup and thermometer and place them on the wet tray. Clear away all the apparatus and leave your bench clean and tidy. Page 5

6 EXPERIMENT 1 EXPERIMENT 2 Mass of calcium metal Mass of calcium carbonate Mass of empty cup Mass of cup plus acid Mass of empty cup Mass of cup plus acid Mass of acid 1 (M 1 ) Mass of acid 2 (M 2 ) TIME (minutes) TEMPERATURE ( O C) EXPERIMENT 1 EXPERIMENT 2 4 ADD THE SOLID FINDING THE TEMPERATURE CHANGES Plot two separate graphs of temperature against time, one for each experiment. Extrapolate the points find out the instantaneous temperature change at the 4 th minute in each reaction. Call these t 1 and t 2. Page 6

7 CALCULATING THE ENERGY CHANGES Take the Specific Heat Capacity (c) for the solutions to be 4.18 J.g -1. O C -1 Take the mass of the solutions to be the mass of acid used in each experiment Ignore the sign of the temperature change (rise or drop) just use the numerical value 1) For Ca metal Heat change = mass of solution 1 c t 1 =. J = kj Moles of Ca = mass of Ca Atomic Wt. (At.Wt. for Ca = 40.1) = Energy per mole = Heat change number of moles =. kj.mol -1 Now decide whether the reaction was exothermic (temperature rise) or endothermic (temperature drop). Use the correct sign convention to write your value for the enthalpy change for this reaction below:- H 1 =.. kj.mol -1 2) For CaCO 3 Heat change = mass of solution 2 c t 2 =. J = kj Moles of CaCO 3 = mass of CaCO 3 Molar Mass (Molar Mass = 100.1) = Energy per mole = Heat change number of moles =. kj.mol -1 Now decide whether the reaction was exothermic or endothermic. Use the correct sign convention to write your value for the enthalpy change for this reaction below:- H 2 =.. kj.mol -1 3) Use Hess Law and your values for H 1 and H 2 and the enthalpies of formation for water and carbon dioxide to calculate the enthalpy of formation for CaCO 3. H 2 (g) + ½O 2 (g) H 2 O (l) H f = kj.mol -1 (call this H 3 ) C (s) + O 2 (g) CO 2 (g) H f = kj.mol -1 (call this H 4 ) Page 7

Transfer of heat energy often occurs during chemical reactions. A reaction

Transfer of heat energy often occurs during chemical reactions. A reaction Chemistry 111 Lab: Thermochemistry Page I-3 THERMOCHEMISTRY Heats of Reaction The Enthalpy of Formation of Magnesium Oxide Transfer of heat energy often occurs during chemical reactions. A reaction may

More information

Thermochemistry: Calorimetry and Hess s Law

Thermochemistry: Calorimetry and Hess s Law Thermochemistry: Calorimetry and Hess s Law Some chemical reactions are endothermic and proceed with absorption of heat while others are exothermic and proceed with an evolution of heat. The magnitude

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

thermometer as simple as a styrofoam cup and a thermometer. In a calorimeter the reactants are placed into the

thermometer as simple as a styrofoam cup and a thermometer. In a calorimeter the reactants are placed into the Thermochemistry Readin assinment: Chan, Chemistry 10 th edition, pp. 249-258. Goals We will become familiar with the principles of calorimetry in order to determine the heats of reaction for endothermic

More information

Thermochemistry I: Endothermic & Exothermic Reactions

Thermochemistry I: Endothermic & Exothermic Reactions THERMOCHEMISTRY I 77 Thermochemistry I: Endothermic & Exothermic Reactions OBJECTIVES: Learn elementary concepts of calorimetry and thermochemistry Practice techniques of careful temperature, mass, and

More information

The Empirical Formula of a Compound

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,

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

Apparatus error for each piece of equipment = 100 x margin of error quantity measured

Apparatus error for each piece of equipment = 100 x margin of error quantity measured 1) Error Analysis Apparatus Errors (uncertainty) Every time you make a measurement with a piece of apparatus, there is a small margin of error (i.e. uncertainty) in that measurement due to the apparatus

More information

SUGGESTION ANSWER SCHEME CHAPTER 8: THERMOCHEMISTRY. 1 (a) Use the data in the table below to answer the following questions:

SUGGESTION ANSWER SCHEME CHAPTER 8: THERMOCHEMISTRY. 1 (a) Use the data in the table below to answer the following questions: SUGGESTION ANSWER SCHEME CHAPTER 8: THERMOCHEMISTRY ANSWER SCHEME UPS 2004/2005 SK027 1 (a) Use the data in the table below to answer the following questions: Enthalpy change ΔH (kj/mol) Atomization energy

More information

The energy level diagram for this reaction is shown below.

The energy level diagram for this reaction is shown below. Q. Methanol can be made when methane reacts with oxygen. (a) The energy level diagram for this reaction is shown below. (i) What is the energy change represented by A? () (ii) Use the energy level diagram

More information

Thermochemical equations allow stoichiometric calculations.

Thermochemical equations allow stoichiometric calculations. CHEM 1105 THERMOCHEMISTRY 1. Change in Enthalpy ( H) Heat is evolved or absorbed in all chemical reactions. Exothermic reaction: heat evolved - heat flows from reaction mixture to surroundings; products

More information

Experiment 6 Coffee-cup Calorimetry

Experiment 6 Coffee-cup Calorimetry 6-1 Experiment 6 Coffee-cup Calorimetry Introduction: Chemical reactions involve the release or consumption of energy, usually in the form of heat. Heat is measured in the energy units, Joules (J), defined

More information

HEAT OF FORMATION OF AMMONIUM NITRATE

HEAT OF FORMATION OF AMMONIUM NITRATE 303 HEAT OF FORMATION OF AMMONIUM NITRATE OBJECTIVES FOR THE EXPERIMENT The student will be able to do the following: 1. Calculate the change in enthalpy (heat of reaction) using the Law of Hess. 2. Find

More information

Unit 6 The Mole Concept

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

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

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

Practical 1: Measure the molar volume of a gas

Practical 1: Measure the molar volume of a gas Practical Student sheet Practical : Wear eye protection. Ensure the delivery tube does not become blocked. Ethanoic acid will sting if it gets into cuts in the skin. Equipment boiling tube stand and clamp

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

PREPARATION FOR CHEMISTRY LAB: COMBUSTION

PREPARATION FOR CHEMISTRY LAB: COMBUSTION 1 Name: Lab Instructor: PREPARATION FOR CHEMISTRY LAB: COMBUSTION 1. What is a hydrocarbon? 2. What products form in the complete combustion of a hydrocarbon? 3. Combustion is an exothermic reaction. What

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

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

IB Chemistry. DP Chemistry Review

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

More information

UNIT 1 THERMOCHEMISTRY

UNIT 1 THERMOCHEMISTRY UNIT 1 THERMOCHEMISTRY THERMOCHEMISTRY LEARNING OUTCOMES Students will be expected to: THERMOCHEMISTRY STSE analyse why scientific and technological activities take place in a variety individual and group

More information

Introductory Chemistry, 3 rd Edition Nivaldo Tro. Roy Kennedy Massachusetts Bay Community College Wellesley Hills, Maqqwertd ygoijpk[l

Introductory Chemistry, 3 rd Edition Nivaldo Tro. Roy Kennedy Massachusetts Bay Community College Wellesley Hills, Maqqwertd ygoijpk[l Introductory Chemistry, 3 rd Edition Nivaldo Tro Quantities in Car an octane and oxygen molecules and carbon dioxide and water Chemical Reactions Roy Kennedy Massachusetts Bay Community College Wellesley

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

Exp 13 Volumetric Analysis: Acid-Base titration

Exp 13 Volumetric Analysis: Acid-Base titration Exp 13 Volumetric Analysis: Acid-Base titration Exp. 13 video (time: 47:17 minutes) Titration - is the measurement of the volume of a standard solution required to completely react with a measured volume

More information

Thermodynamics. Thermodynamics 1

Thermodynamics. Thermodynamics 1 Thermodynamics 1 Thermodynamics Some Important Topics First Law of Thermodynamics Internal Energy U ( or E) Enthalpy H Second Law of Thermodynamics Entropy S Third law of Thermodynamics Absolute Entropy

More information

Summer Holidays Questions

Summer Holidays Questions Summer Holidays Questions Chapter 1 1) Barium hydroxide reacts with hydrochloric acid. The initial concentration of the 1 st solution its 0.1M and the volume is 100ml. The initial concentration of the

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

Determination of the enthalpy of combustion using a bomb calorimeter TEC

Determination of the enthalpy of combustion using a bomb calorimeter TEC Determination of the enthalpy of TEC Related concepts First law of thermodynamics, Hess s law of constant heat summation, enthalpy of combustion, enthalpy of formation, heat capacity. Principle The bomb

More information

SUPPLEMENTARY TOPIC 3 ENERGY AND CHEMICAL REACTIONS

SUPPLEMENTARY TOPIC 3 ENERGY AND CHEMICAL REACTIONS SUPPLEMENTARY TOPIC 3 ENERGY AND CHEMICAL REACTIONS Rearranging atoms. In a chemical reaction, bonds between atoms in one or more molecules (reactants) break and new bonds are formed with other atoms to

More information

EXPERIMENT 12: Empirical Formula of a Compound

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

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

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.

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

More information

Unit 5 Practice Test. Name: Class: Date: Multiple Choice Identify the choice that best completes the statement or answers the question.

Unit 5 Practice Test. Name: Class: Date: Multiple Choice Identify the choice that best completes the statement or answers the question. Name: Class: Date: Unit 5 Practice Test Multiple Choice Identify the choice that best completes the statement or answers the question. 1) The internal energy of a system is always increased by. A) adding

More information

Mixtures and Pure Substances

Mixtures and Pure Substances Unit 2 Mixtures and Pure Substances Matter can be classified into two groups: mixtures and pure substances. Mixtures are the most common form of matter and consist of mixtures of pure substances. They

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

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

Determination of a Chemical Formula

Determination of a Chemical Formula 1 Determination of a Chemical Formula Introduction Molar Ratios Elements combine in fixed ratios to form compounds. For example, consider the compound TiCl 4 (titanium chloride). Each molecule of TiCl

More information

Chemical reactions allow living things to grow, develop, reproduce, and adapt.

Chemical reactions allow living things to grow, develop, reproduce, and adapt. Section 2: Chemical reactions allow living things to grow, develop, reproduce, and adapt. K What I Know W What I Want to Find Out L What I Learned Essential Questions What are the parts of a chemical reaction?

More information

Experiment 12- Classification of Matter Experiment

Experiment 12- Classification of Matter Experiment Experiment 12- Classification of Matter Experiment Matter can be classified into two groups: mixtures and pure substances. Mixtures are the most common form of matter and consist of mixtures of pure substances.

More information

Moles and Chemical Reactions. Moles and Chemical Reactions. Molar mass = 2 x 12.011 + 6 x 1.008 + 1 x15.999 = 46.069 g/mol

Moles and Chemical Reactions. Moles and Chemical Reactions. Molar mass = 2 x 12.011 + 6 x 1.008 + 1 x15.999 = 46.069 g/mol 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

Energy and Chemical Reactions. Characterizing Energy:

Energy and Chemical Reactions. Characterizing Energy: Energy and Chemical Reactions Energy: Critical for virtually all aspects of chemistry Defined as: We focus on energy transfer. We observe energy changes in: Heat Transfer: How much energy can a material

More information

ACID-BASE TITRATIONS: DETERMINATION OF CARBONATE BY TITRATION WITH HYDROCHLORIC ACID BACKGROUND

ACID-BASE TITRATIONS: DETERMINATION OF CARBONATE BY TITRATION WITH HYDROCHLORIC ACID BACKGROUND #3. Acid - Base Titrations 27 EXPERIMENT 3. ACID-BASE TITRATIONS: DETERMINATION OF CARBONATE BY TITRATION WITH HYDROCHLORIC ACID BACKGROUND Carbonate Equilibria In this experiment a solution of hydrochloric

More information

Chemical Calculations: The Mole Concept and Chemical Formulas. AW Atomic weight (mass of the atom of an element) was determined by relative weights.

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.

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

CHEMICAL REACTIONS OF COPPER AND PERCENT YIELD KEY

CHEMICAL REACTIONS OF COPPER AND PERCENT YIELD KEY CHEMICAL REACTIONS OF COPPER AND PERCENT YIELD Objective To gain familiarity with basic laboratory procedures, some chemistry of a typical transition element, and the concept of percent yield. Apparatus

More information

Stoichiometry Limiting Reagent Laboratory. Chemistry 118 Laboratory University of Massachusetts, Boston

Stoichiometry Limiting Reagent Laboratory. Chemistry 118 Laboratory University of Massachusetts, Boston Chemistry 118 Laboratory University of Massachusetts, Boston STOICHIOMETRY - LIMITING REAGENT --------------------------------------------------------------------------------------------------------------------------------------------

More information

Adiabatic Bomb Calorimetry

Adiabatic Bomb Calorimetry CHEM 366 II-1 Adiabatic Bomb Calorimetry Introduction Obtaining energy in the form of heat from the combustion or oxidation of thermodynamically unstable (and often kinetically inert) hydrocarbons and

More information

Standard Free Energies of Formation at 298 K. Average Bond Dissociation Energies at 298 K

Standard Free Energies of Formation at 298 K. Average Bond Dissociation Energies at 298 K 1 Thermodynamics There always seems to be at least one free response question that involves thermodynamics. These types of question also show up in the multiple choice questions. G, S, and H. Know what

More information

Review and apply Investigation 5. Let s review Pages 311-312

Review and apply Investigation 5. Let s review Pages 311-312 Review and apply Investigation 5 Let s review Pages 311-312 1. After you tested all the known powders with all the test liquids, describe what you did to identify the unknown powder. Students should have

More information

Q1. A student studied the reaction between dilute hydrochloric acid and an excess of calcium carbonate.

Q1. A student studied the reaction between dilute hydrochloric acid and an excess of calcium carbonate. Q. A student studied the reaction between dilute hydrochloric acid and an excess of calcium carbonate. calcium carbonate + hydrochloric acid calcium chloride + water + carbon dioxide The student measured

More information

Enthalpy of Reaction and Calorimetry worksheet

Enthalpy of Reaction and Calorimetry worksheet Enthalpy of Reaction and Calorimetry worksheet 1. Calcium carbonate decomposes at high temperature to form carbon dioxide and calcium oxide, calculate the enthalpy of reaction. CaCO 3 CO 2 + CaO 2. Carbon

More information

Unit 19 Practice. Name: Class: Date: Multiple Choice Identify the choice that best completes the statement or answers the question.

Unit 19 Practice. Name: Class: Date: Multiple Choice Identify the choice that best completes the statement or answers the question. Name: Class: Date: Unit 19 Practice Multiple Choice Identify the choice that best completes the statement or answers the question. 1) The first law of thermodynamics can be given as. A) E = q + w B) =

More information

AP CHEMISTRY 2013 SCORING GUIDELINES

AP CHEMISTRY 2013 SCORING GUIDELINES AP CHEMISTRY 2013 SCORING GUIDELINES Question 4 (15 points) For each of the following three reactions, write a balanced equation for the reaction in part (i) and answer the question about the reaction

More information

BLOWING UP BALLOONS, chemically

BLOWING UP BALLOONS, chemically BLOWING UP BALLOONS, chemically PRE LAB DISCUSSION: Today we will be using a closed system. A closed system does not permit matter to enter or exit the apparatus. Lavoisier's classic 12-day experiment,

More information

Chemistry 12 Worksheet 1-1 - Measuring Reaction Rates

Chemistry 12 Worksheet 1-1 - Measuring Reaction Rates Chemistry 12 Worksheet 1-1 - Measuring Reaction Rates 1. A chemist wishes to determine the rate of reaction of zinc with hydrochloric acid. The equation for the reaction is: Zn (s) + 2HCl (aq) oh 2(g)

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

Reaction of Magnesium with Hydrochloric Acid (Gas Laws) Chemicals Needed:

Reaction of Magnesium with Hydrochloric Acid (Gas Laws) Chemicals Needed: Reaction of Magnesium with Hydrochloric Acid (Gas Laws) Your Name: Date: Partner(s) Names: Objectives: React magnesium metal with hydrochloric acid, collecting the hydrogen over water. Calculate the grams

More information

Test Review # 9. Chemistry R: Form TR9.13A

Test Review # 9. Chemistry R: Form TR9.13A Chemistry R: Form TR9.13A TEST 9 REVIEW Name Date Period Test Review # 9 Collision theory. In order for a reaction to occur, particles of the reactant must collide. Not all collisions cause reactions.

More information

CHEM 105 HOUR EXAM III 28-OCT-99. = -163 kj/mole determine H f 0 for Ni(CO) 4 (g) = -260 kj/mole determine H f 0 for Cr(CO) 6 (g)

CHEM 105 HOUR EXAM III 28-OCT-99. = -163 kj/mole determine H f 0 for Ni(CO) 4 (g) = -260 kj/mole determine H f 0 for Cr(CO) 6 (g) CHEM 15 HOUR EXAM III 28-OCT-99 NAME (please print) 1. a. given: Ni (s) + 4 CO (g) = Ni(CO) 4 (g) H Rxn = -163 k/mole determine H f for Ni(CO) 4 (g) b. given: Cr (s) + 6 CO (g) = Cr(CO) 6 (g) H Rxn = -26

More information

Where the exp subscripts refer to the experimental temperature and pressure acquired in the laboratory.

Where the exp subscripts refer to the experimental temperature and pressure acquired in the laboratory. Molar Volume of Carbon Dioxide Reading assignment: Julia Burdge, Chemistry 3rd edition, Chapter 10. Goals To determine the molar volume of carbon dioxide gas and the amount of sodium carbonate in a sample.

More information

87 16 70 20 58 24 44 32 35 40 29 48 (a) graph Y versus X (b) graph Y versus 1/X

87 16 70 20 58 24 44 32 35 40 29 48 (a) graph Y versus X (b) graph Y versus 1/X HOMEWORK 5A Barometer; Boyle s Law 1. The pressure of the first two gases below is determined with a manometer that is filled with mercury (density = 13.6 g/ml). The pressure of the last two gases below

More information

Determination of the enthalpy of combustion using a bomb calorimeter TEC. Safety precautions

Determination of the enthalpy of combustion using a bomb calorimeter TEC. Safety precautions Safety precautions Naphthalene is harmful if swallowed. May cause cancer. Is further very toxic to aquatic organisms and can have long-term harmful effects in bodies of water. Equipment 1 Bomb calorimeter

More information

Stoichiometry. Lecture Examples Answer Key

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

More information

Chapter 3! Stoichiometry: Calculations with Chemical Formulas and Equations. Stoichiometry

Chapter 3! Stoichiometry: Calculations with Chemical Formulas and Equations. Stoichiometry Chapter 3! : Calculations with Chemical Formulas and Equations Anatomy of a Chemical Equation CH 4 (g) + 2O 2 (g) CO 2 (g) + 2 H 2 O (g) Anatomy of a Chemical Equation CH 4 (g) + 2 O 2 (g) CO 2 (g) + 2

More information

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 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

More information

Chemistry 151 Final Exam

Chemistry 151 Final Exam Chemistry 151 Final Exam Name: SSN: Exam Rules & Guidelines Show your work. No credit will be given for an answer unless your work is shown. Indicate your answer with a box or a circle. All paperwork must

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

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

Return to Lab Menu. Stoichiometry Exploring the Reaction between Baking Soda and Vinegar

Return to Lab Menu. Stoichiometry Exploring the Reaction between Baking Soda and Vinegar Return to Lab Menu Stoichiometry Exploring the Reaction between Baking Soda and Vinegar Objectives -to observe and measure mass loss in a gas forming reaction -to calculate CO 2 loss and correlate to a

More information

Recovery of Elemental Copper from Copper (II) Nitrate

Recovery of Elemental Copper from Copper (II) Nitrate Recovery of Elemental Copper from Copper (II) Nitrate Objectives: Challenge: Students should be able to - recognize evidence(s) of a chemical change - convert word equations into formula equations - perform

More information

Final Exam Review. I normalize your final exam score out of 70 to a score out of 150. This score out of 150 is included in your final course total.

Final Exam Review. I normalize your final exam score out of 70 to a score out of 150. This score out of 150 is included in your final course total. Final Exam Review Information Your ACS standardized final exam is a comprehensive, 70 question multiple choice (a d) test featuring material from BOTH the CHM 101 and 102 syllabi. Questions are graded

More information

MOLES AND MOLE CALCULATIONS

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

More information

Stoichiometry Limiting Reagent Laboratory. Chemistry 118 Laboratory University of Massachusetts, Boston

Stoichiometry Limiting Reagent Laboratory. Chemistry 118 Laboratory University of Massachusetts, Boston Chemistry 118 Laboratory University of Massachusetts, Boston STOICHIOMETRY - LIMITING REAGENT -----------------------------------------------------------------------------------------------------------------------------

More information

Experiment 3 Limiting Reactants

Experiment 3 Limiting Reactants 3-1 Experiment 3 Limiting Reactants Introduction: Most chemical reactions require two or more reactants. Typically, one of the reactants is used up before the other, at which time the reaction stops. The

More information

Determination of the Empirical Formula of Magnesium Oxide

Determination of the Empirical Formula of Magnesium Oxide Determination of the Empirical Formula of Magnesium Oxide GOAL AND OVERVIEW The quantitative stoichiometric relationships governing mass and amount will be studied using the combustion reaction of magnesium

More information

Enthalpy of Combustion via Calorimetry

Enthalpy of Combustion via Calorimetry Enthalpy of Combustion via Calorimetry Introduction This experiment measures the enthalpy change when a system consisting of a known amount of a substance in the presence of excess oxygen is quantitatively

More information

Experiment 8: Chemical Moles: Converting Baking Soda to Table Salt

Experiment 8: Chemical Moles: Converting Baking Soda to Table Salt Experiment 8: Chemical Moles: Converting Baking Soda to Table Salt What is the purpose of this lab? We want to develop a model that shows in a simple way the relationship between the amounts of reactants

More information

Instructions Answer all questions in the spaces provided. Do all rough work in this book. Cross through any work you do not want to be marked.

Instructions Answer all questions in the spaces provided. Do all rough work in this book. Cross through any work you do not want to be marked. GCSE CHEMISTRY Higher Tier Chemistry 1H H Specimen 2018 Time allowed: 1 hour 45 minutes Materials For this paper you must have: a ruler a calculator the periodic table (enclosed). Instructions Answer all

More information

STATE UNIVERSITY OF NEW YORK COLLEGE OF TECHNOLOGY CANTON, NEW YORK COURSE OUTLINE CHEM 150 - COLLEGE CHEMISTRY I

STATE UNIVERSITY OF NEW YORK COLLEGE OF TECHNOLOGY CANTON, NEW YORK COURSE OUTLINE CHEM 150 - COLLEGE CHEMISTRY I STATE UNIVERSITY OF NEW YORK COLLEGE OF TECHNOLOGY CANTON, NEW YORK COURSE OUTLINE CHEM 150 - COLLEGE CHEMISTRY I PREPARED BY: NICOLE HELDT SCHOOL OF SCIENCE, HEALTH, AND PROFESSIONAL STUDIES SCIENCE DEPARTMENT

More information

Chem 1A Exam 2 Review Problems

Chem 1A Exam 2 Review Problems Chem 1A Exam 2 Review Problems 1. At 0.967 atm, the height of mercury in a barometer is 0.735 m. If the mercury were replaced with water, what height of water (in meters) would be supported at this pressure?

More information

MEMORANDUM GRADE 11. PHYSICAL SCIENCES: CHEMISTRY Paper 2

MEMORANDUM GRADE 11. PHYSICAL SCIENCES: CHEMISTRY Paper 2 MEMORANDUM GRADE 11 PHYSICAL SCIENCES: CHEMISTRY Paper 2 MARKS: 150 TIME: 3 hours Learning Outcomes and Assessment Standards LO1 LO2 LO3 AS 11.1.1: Plan and conduct a scientific investigation to collect

More information

Mr. Bracken. Multiple Choice Review: Thermochemistry

Mr. Bracken. Multiple Choice Review: Thermochemistry Mr. Bracken AP Chemistry Name Period Multiple Choice Review: Thermochemistry 1. If this has a negative value for a process, then the process occurs spontaneously. 2. This is a measure of how the disorder

More information

Unit 3 Notepack Chapter 7 Chemical Quantities Qualifier for Test

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?

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

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

CHEMICAL REACTIONS AND REACTING MASSES AND VOLUMES

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

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

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

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

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

More information

Physical Properties of a Pure Substance, Water

Physical Properties of a Pure Substance, Water Physical Properties of a Pure Substance, Water The chemical and physical properties of a substance characterize it as a unique substance, and the determination of these properties can often allow one to

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

Mole Notes.notebook. October 29, 2014

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

More information

Experiment 7: Titration of an Antacid

Experiment 7: Titration of an Antacid 1 Experiment 7: Titration of an Antacid Objective: In this experiment, you will standardize a solution of base using the analytical technique known as titration. Using this standardized solution, you will

More information

Chemistry 112 Laboratory Experiment 6: The Reaction of Aluminum and Zinc with Hydrochloric Acid

Chemistry 112 Laboratory Experiment 6: The Reaction of Aluminum and Zinc with Hydrochloric Acid Chemistry 112 Laboratory Experiment 6: The Reaction of Aluminum and Zinc with Hydrochloric Acid Introduction Many metals react with acids to form hydrogen gas. In this experiment, you will use the reactions

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

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

Chapter Test B. Chapter: Measurements and Calculations

Chapter Test B. Chapter: Measurements and Calculations Assessment Chapter Test B Chapter: Measurements and Calculations PART I In the space provided, write the letter of the term or phrase that best completes each statement or best answers each question. 1.

More information

Unit 2: Quantities in Chemistry

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

More information