5.2. Determining Enthalpy of Reaction by Experiment. Specific Heat Capacity. 234 MHR Unit 3 Energy Changes and Rates of Reaction

Save this PDF as:

Size: px
Start display at page:

Download "5.2. Determining Enthalpy of Reaction by Experiment. Specific Heat Capacity. 234 MHR Unit 3 Energy Changes and Rates of Reaction"

Transcription

1 In this section, you will 5.2 Section Preview/ Specific Expectations determine the heat that is produced by a reaction using a calorimeter, and use the data obtained to calculate the enthalpy change for the reaction communicate your understanding of the following terms: specific heat capacity (c), heat capacity (C), calorimeter, coffee-cup calorimeter, constantpressure calorimeter Figure 5.12 On a sunny day, you would probably prefer to sit on a bench made of wood rather than a bench made of aluminum. Wood has a higher heat capacity than aluminum. Therefore, more heat is needed to increase its temperature. Explain why water is sometimes used as a coolant for automobile engines. Determining Enthalpy of Reaction by Experiment Chemical and physical processes, such as the ones you studied in section 5.1, are associated with characteristic enthalpy changes. How do chemists measure these enthalpy changes? To measure the enthalpy of a chemical or physical process, chemists insulate the system from the surroundings. They can then determine the heat change by measuring the temperature change of the system. What is the relationship between the heat change and the temperature change? As you learned in previous science courses, each substance has a characteristic property that dictates how its temperature will change when heat is lost or gained. Specific Heat Capacity The amount of energy that is needed to raise the temperature of one gram of a substance 1 C (or 1 K) is the specific heat capacity, c, of the substance. Specific heat capacity is usually expressed in units of J/g C. The specific heat capacities of several substances are given in Table 5.2. Figure 5.12 shows that you can often predict the relative specific heat capacities of familiar substances. Table 5.2 Specific Heat Capacities of Selected Substances Substance aluminum carbon (graphite) hydrogen iron ammonia (liquid) ethanol ethylene glycol water (liquid) air concrete glass wood Element Compound Other material Specific heat capacity (J/g C at 25 C) You can use the specific heat capacity of a substance to calculate the amount of energy that is needed to heat a given mass a certain number of degrees. You can also use the specific heat capacity to determine the amount of heat that is released when the temperature of a given mass decreases. The specific heat capacity of liquid water, as shown in Table 5.2, is J/g C. This relatively large value indicates that a considerable amount of energy is needed to raise or lower the temperature of water. 234 MHR Unit 3 Energy Changes and Rates of Reaction

2 All samples of the same substance have the same specific heat capacity. In contrast, heat capacity, C, relates the heat of a sample, object, or system to its change in temperature. Heat capacity is usually expressed in units of kj/ C. Consider a bathtub full of water and a teacup full of water at room temperature. All the water has the same specific heat capacity, but the two samples have different heat capacities. It would take a great deal more heat to raise the temperature of the water in the bathtub by 10 C than it would take to raise the temperature of the water in the teacup by 10 C. Therefore, the water in the bathtub has a higher heat capacity. Specific Heat Capacity and Heat Transfer You can use the following equation to calculate the heat change of a substance, based on the mass of the substance. You can also use this equation to calculate the specific heat capacity of the substance and the change in its temperature. Q = m c T where Q = heat (J) m = mass (g) c = specific heat capacity (J/g C) T = T f (final temperature) T i (initial temperature)( C ork) Water is often used in controlled surroundings to measure the heat of a reaction. For example, you can use the equation above to determine the amount of energy that is needed to heat g of water from 20.0 C to 45.0 C. Q = m c T The mass of the water is g. The specific heat capacity of water is J/g C. The temperature of the water increases by 25.0 C. Q = ( g)(4.184 J/g C)(25.0 C) = J To raise the temperature of g of water by 25 C, J of heat is needed. Try the following problems to practise working with specific heat capacity and temperature change. Practice Problems 5. A sample of ethylene glycol, used in car radiators, has a mass of 34.8 g. The sample liberates 783 J of heat. The initial temperature of the sample is 22.1 C. What is the final temperature? 6. A sample of ethanol, C 2 H 5 OH, absorbs 23.4 kj of energy. The temperature of the sample increases from 5.6 C to 19.8 C. What is the mass of the ethanol sample? The specific heat capacity of ethanol is 2.46 J/g C. 7. A child s swimming pool contains 1000 L of water. When the water is warmed by solar energy, its temperature increases from 15.3 C to 21.8 C. How much heat does the water absorb? 8. What temperature change results from the loss of 255 kj from a 10.0 kg sample of water? Chapter 5 Energy and Change MHR 235

3 Web LINK chemistry12 The famous French scientist Antoine Laviosier ( ) is considered by many to be the first modern chemist. Lavoisier created a calorimeter to study the energy that is released by the metabolism of a guinea pig. To learn about Lavoisier s experiment, go to the web site above and click on Web Links. What do you think about using animals in experiments? Write an essay to explain why you agree or disagree with this practice. Measuring Heat Transfer in a Laboratory From previous science courses, you will probably remember that a calorimeter is used to measure enthalpy changes for chemical and physical reactions. A calorimeter works by insulating a system from its surroundings. By measuring the temperature change of the system, you can determine the amount of heat that is released or absorbed by the reaction. For example, the heat that is released by an exothermic reaction raises the temperature of the system. Q reaction = Q insulated system In your previous chemistry course, you learned about various types of calorimeters. For instance, you learned about a bomb calorimeter, which allows chemists to determine energy changes under conditions of constant volume. In section 5.1, however, you learned that an enthalpy change represents the heat change between products and reactants at a constant pressure. Therefore, the calorimeter you use to determine an enthalpy change should allow the reaction to be carried out at a constant pressure. In other words, it should be open to the atmosphere. To determine enthalpy changes in high school laboratories, a coffee-cup calorimeter provides fairly accurate results. A coffee-cup calorimeter is composed of two nested polystyrene cups ( coffee cups ). They can be placed in a 250 ml beaker for added stability. Since a coffee-cup calorimeter is open to the atmosphere, it is also called a constant-pressure calorimeter. As with any calorimeter, each part of the coffee-cup calori-meter has an associated heat capacity. Because these heat capacities are very small, however, and because a coffee-cup calorimeter is not as accurate as other calorimeters, the heat capacity of a coffee-cup calorimeter is usually assumed to be negligible. It is assumed to have a value of 0 J/ C. Using a Calorimeter to Determine the Enthalpy of a Reaction A coffee-cup calorimeter is well-suited to determining the enthalpy changes of reactions in dilute aqueous solutions. The water in the calorimeter absorbs (or provides) the energy that is released (or absorbed) by a chemical reaction. When carrying out an experiment in a dilute solution, the solution itself absorbs or releases the energy. You can calculate the amount of energy that is absorbed or released by the solution using the equation mentioned earlier. Q = m c T The mass, m, is the mass of the solution, because the solution absorbs the heat. When a dilute aqueous solution is used in a calorimeter, you can assume that the solution has the same density and specific heat capacity as pure water. As you saw above, you can also assume that the heat capacity of the calorimeter is negligible. In other words, you can assume that all the heat that is released or absorbed by the reaction is absorbed or released by the solution. The following Sample Problem illustrates how calorimetry can be used to determine H of a chemical reaction. 236 MHR Unit 3 Energy Changes and Rates of Reaction

4 Sample Problem Determining the Enthalpy of a Chemical Reaction Problem Copper(II) sulfate, CuSO 4, reacts with sodium hydroxide, NaOH, in a double displacement reaction. A precipitate of copper(ii) hydroxide, Cu(OH) 2, and aqueous sodium sulfate, Na 2 SO 4, is produced. CuSO 4(aq) + 2NaOH (aq) Cu(OH) 2(s) + Na 2 SO 4(aq) 50.0 ml of mol/l CuSO 4 solution is mixed with an equal volume of mol/l NaOH. The initial temperature of both solutions is 21.4 C. After mixing the solutions in the coffee-cup calorimeter, the highest temperature that is reached is 24.6 C. Determine the enthalpy change of the reaction. Then write the thermochemical equation. What Is Required? You need to calculate H of the given reaction. What Is Given? You know the volume of each solution. You also know the initial temperature of each solution and the final temperature of the reaction mixture. Volume of CuSO 4 solution, V CuSO4 = 50.0 ml Volume of NaOH solution, V NaOH = 50.0 ml Initial temperature, T i = 21.4 C Final temperature, T f = 24.6 C Plan Your Strategy Step 1 Determine the total volume by adding the volumes of the two solutions. Determine the total mass of the reaction mixture, assuming a density of 1.00 g/ml (the density of water). Step 2 Use the equation Q = m c T to calculate the amount of heat that is absorbed by the solution (in J). Assume that the reaction mixture has the same specific heat capacity as water (c = J/g C). Step 3 Use the equation Q reaction = Q solution to determine the amount of heat that is released by the reaction. Step 4 Determine the number of moles of CuSO 4 and NaOH that reacted. If necessary, determine the limiting reactant. Use the amount of limiting reactant to get H of the reaction (in kj/mol). Step 5 Use your H to write the thermochemical equation for the reaction. Act on Your Strategy Step 1 The total volume of the reaction mixture is 50.0 ml ml = ml The mass of the reaction mixture, assuming a density of 1.00 g/ml, is m = DV = (1.00 g/ml)(100.0 ml) = g Continued... Chapter 5 Energy and Change MHR 237

5 Continued... Step 2 The amount of heat, Q, that is absorbed by the solution is Q solution = m solution c solution T solution = (100 g)(4.184 J/g C)(24.6 C 21.4 C) = J Step 3 Based on the value of Q in step 2, the heat change for the reaction is J. Step 4 Calculate the number of moles of CuSO 4 as follows. n = c V = (0.300 mol/l)( L) = mol Calculate the number of moles of NaOH. n mol NaOH = (0.600 mol/l)( L) = mol The reactants are present in stoichiometric amounts. (There is no limiting reactant.) H of the reaction, in kj/mol CuSO 4, is H = J mol CuSO 4 = J/mol CuSO 4 = 89 kj/mol CuSO 4 The enthalpy change of the reaction is 89 kj/mol CuSO 4. Step 5 The thermochemical equation is CuSO 4(aq) + 2NaOH (aq) Cu(OH) 2(s) + Na 2 SO 4(aq) H = 89 kj Check Your Solution The solution has the correct number of significant digits. The units are correct. You know that the reaction was exothermic, because the temperature of the solution increased. The calculated H is negative, which is correct for an exothermic reaction. Practice Problems 9. A chemist wants to determine the enthalpy of neutralization for the following reaction. HCl (aq) + NaOH (aq) NaCl (aq) + H 2 O (l) The chemist uses a coffee-cup calorimeter to neutralize completely 61.1 ml of mol/l HCl (aq) with 42.6 ml of NaOH (aq). The initial temperature of both solutions is 17.8 C. After neutralization, the highest recorded temperature is 21.6 C. Calculate the enthalpy of neutralization, in units of kj/mol of HCl. Assume that the density of both solutions is 1.00 g/ml. Also assume that the specific heat capacity of both solutions is the same as the specific heat capacity of water. 238 MHR Unit 3 Energy Changes and Rates of Reaction

6 10. A chemist wants to determine empirically the enthalpy change for the following reaction. Mg (s) + 2HCl (aq) MgCl 2(aq) + H 2(g) The chemist uses a coffee-cup calorimeter to react 0.50 g of Mg ribbon with 100 ml of 1.00 mol/l HCl (aq). The initial temperature of the HCl (aq) is 20.4 C. After neutralization, the highest recorded temperature is 40.7 C. (a) Calculate the enthalpy change, in kj/mol of Mg, for the reaction. (b) State any assumptions that you made in order to determine the enthalpy change. 11. Nitric acid is neutralized with potassium hydroxide in the following reaction. HNO 3(aq) + KOH (aq) KNO 3(aq) + H 2 O (l) H = 53.4 kj/mol 55.0 ml of 1.30 mol/l solutions of both reactants, at 21.4 C, are mixed in a calorimeter. What is the final temperature of the mixture? Assume that the density of both solutions is 1.00 g/ml. Also assume that the specific heat capacity of both solutions is the same as the specific heat capacity of water. No heat is lost to the calorimeter itself. 12. A student uses a coffee-cup calorimeter to determine the enthalpy of reaction for hydrobromic acid and potassium hydroxide. The student mixes ml of 0.50 mol/l HBr (aq) at 21.0 C with ml of 0.50 mol/l KOH (aq), also at 21.0 C. The highest temperature that is reached is 24.4 C. Write a thermochemical equation for the reaction. In Practice Problems 9, 11, and 12, you used experimental data to determine the enthalpy of reaction for neutralization reactions. Neutralization reactions are particularly well suited to analysis involving the use of a coffee-cup calorimeter for a number of reasons: When using dilute solutions of acids and bases, you can assume their density is close to the density of water. Therefore, you can easily measure the volume of the solutions and calculate their mass. Neutralization reactions between dilute strong acids and dilute strong bases tend to cause temperature changes in the reaction mixture that are large enough to be measurable using a standard thermometer, but small enough for safety. Neutralization reactions take place very quickly. Therefore, the peak temperature change also occurs very quickly. There is little time for heat transfer between the insulated system and the surroundings to take place. In the following investigation, you will construct a coffee-cup calorimeter and use it to determine the enthalpy of a neutralization reaction. Chapter 5 Energy and Change MHR 239

Calorimeter: A device in which the heat associated with a specific process is measured.

1 CALORIMETRY p. 661-667 (simple), 673-675 (bomb) Calorimeter: A device in which the heat associated with a specific process is measured. There are two basic types of calorimeters: 1. Constant-pressure

Calorimetry and Enthalpy. Chapter 5.2

Calorimetry and Enthalpy Chapter 5.2 Heat Capacity Specific heat capacity (c) is the quantity of thermal energy required to raise the temperature of 1g of a substance by 1⁰C The units for specific heat

Chemistry Guide

551534 - Chemistry Guide 1- Contents Question Item Objective Type Skill 1 0102 M03.02.04 Multiple-choice answer Mastery of Problem Solving 2 0099 M03.03.02 Multiple-choice answer Mastery of Concepts 3

HEATS OF REACTION. Name: Chemistry 117 Laboratory University of Massachusetts Boston LEARNING GOALS

Name: Chemistry 117 Laboratory University of Massachusetts Boston HEATS OF REACTION LEARNING GOALS 1. Become familiar the technique of calorimetry to measure heats of reaction 2. Become familiar with the

Enthalpy of Neutralization. Introduction

Enthalpy of Neutralization Introduction Energy changes always accompany chemical reactions. If energy, in the form of heat, is liberated the reaction is exothermic and if energy is absorbed the reaction

Example. c. Calculate the amount of heat (in kj) required to heat 1.00 kg (~1 L) of water at 25 C to its boiling point.

Example When consuming an ice-cold drink, one must raise the temperature of the beverage to 37.0 C (normal body temperature). Can one lose weight by drinking ice-cold beverages if the body uses up about

The Relationships Between. Internal Energy, Heat, Enthalpy, and Calorimetry

The Relationships Between Internal Energy, Heat, Enthalpy, and Calorimetry Recap of Last Class Last class, we began our discussion about energy changes that accompany chemical reactions Chapter 5 discusses:

Lab Session 9, Experiment 8: Calorimetry, Heat of Reaction

Lab Session 9, Experiment 8: Calorimetry, Heat of Reaction Specific heat is an intensive property of a single phase (solid, liquid or gas) sample that describes how the temperature of the sample changes

Chapter 5: thermochemstry. Internal Energy: E

Chapter 5: thermochemstry tonight s goals Energy and Enthalpy Review Enthalpies of Reaction Calorimetry Hess Law Enthalpies of Formation Internal Energy: E E = The sum of all kinetic and potential energies

EXPERIMENT 12N CALORIMETRY

EXPERIMENT 12N CALORIMETRY FV 7/28/2016 MATERIALS: PURPOSE: OBJECTIVES: Styrofoam cup and lid, stir bar, magnetic stir plate, digital thermometer, 250 ml beaker, two 100 ml graduated cylinders, aluminum

Lab 9. Hess s Law. Reaction B. NaOH (s) + HCl (aq) NaCl (aq) + H 2 O (l) Reaction C. NaOH (aq) + HCl (aq) NaCl (aq) + H 2 O (l)

Lab 9. Hess s Law Prelab Assignment Before coming to lab: This exercise does not require a report in your lab notebook. Use a pen to record your data, observations, calculations and analysis in the spaces

THERMOCHEMISTRY & DEFINITIONS

THERMOCHEMISTRY & DEFINITIONS Thermochemistry is the study of the study of relationships between chemistry and energy. All chemical changes and many physical changes involve exchange of energy with the

4. Aluminum chloride is 20.2% aluminum by mass. Calculate the mass of aluminum in a 35.0 gram sample of aluminum chloride.

1. Calculate the molecular mass of table sugar sucrose (C 12 H 22 O 11 ). A. 342.30 amu C. 320.05 amu B. 160.03 amu D. 171.15 amu 2. How many oxygen atoms are in 34.5 g of NaNO 3? A. 2.34 10 23 atoms C.

Experiment 25: Calorimetry

Aaron Bunch CHEM 111 Morning Lab 27 October 2014 Experiment 25: Calorimetry Conclusion: The unknown metal #14 has a specific heat of 0.36 J/g C; the heat of neutralization of HCl and NaOH is -53.0 kj/mol

Heat of Neutralization

Cautions HCl and NaOH are corrosive and toxic Purpose The purpose of this experiment is to determine the heat of neutralization for a reaction between a strong acid and a strong base. Introduction Chemical

CHM111 Lab Enthalpy of Hydration of Sodium Acetate Grading Rubric

Name Team Name CHM111 Lab Enthalpy of Hydration of Sodium Acetate Grading Rubric Criteria Points possible Points earned Lab Performance Printed lab handout and rubric was brought to lab 3 Safety and proper

Unit 27 Heat of Neutralization Calorimetry

Unit 27 Heat of Neutralization Calorimetry When reactions occur, energy is always involved. Reactions that absorb energy are called "endothermic" reactions. Reactions that give off energy are called "exothermic"

Tutorial 4 SOLUTION STOICHIOMETRY. Solution stoichiometry calculations involve chemical reactions taking place in solution.

T-27 Tutorial 4 SOLUTION STOICHIOMETRY Solution stoichiometry calculations involve chemical reactions taking place in solution. Of the various methods of expressing solution concentration the most convenient

ENERGY. Thermochemistry. Heat. Temperature & Heat. Thermometers & Temperature. Temperature & Heat. Energy is the capacity to do work.

ENERGY Thermochemistry Energy is the capacity to do work. Chapter 6 Kinetic Energy thermal, mechanical, electrical, sound Potential Energy chemical, gravitational, electrostatic Heat Heat, or thermal energy,

System. System, Boundary and surroundings: Nature of heat and work: Sign convention of heat: Unit-7 Thermodynamics

Unit-7 Thermodynamics Introduction: The term Thermo means heat and dynamics means flow or movement.. So thermodynamics is concerned with the flow of heat. The different forms of the energy are interconvertible

Name Date Class THERMOCHEMISTRY. SECTION 17.1 THE FLOW OF ENERGY HEAT AND WORK (pages 505 510)

17 THERMOCHEMISTRY SECTION 17.1 THE FLOW OF ENERGY HEAT AND WORK (pages 505 510) This section explains the relationship between energy and heat, and distinguishes between heat capacity and specific heat.

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

Experiment 14 - Heats of Reactions

Experiment 14 - Heats of Reactions If a chemical reaction is carried out inside a calorimeter, the heat evolved or absorbed by the reaction can be determined. A calorimeter is an insulated container, and

Chapter 5 Thermochemistry

Chapter 5 Thermochemistry I. Nature of Energy Energy units SI unit is joule, J From E = 1/2 mv 2, 1J = 1kg. m 2 /s 2 Traditionally, we use the calorie as a unit of energy. 1 cal = 4.184J (exactly) The

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

Heats of Reaction lab. Enthalpy

Heats of Reaction lab tonight s QuestiONs Is the amount of heat given off or absorbed, q sys, by a chemical reaction an intensive or extensive property? For an acid-base reaction, does the heat of reaction

Calorimetry and Thermochemistry

CHEM 121L General Chemistry Laboratory Revision 1.3 Calorimetry and Thermochemistry Learn how to measure Heat flow. Learn about the Specific Heat of substances. Learn about Exothermic and Endothermic chemical

Additivity of Heats of Reaction: Hess s Law

Additivity of Heats of Reaction: Hess s Law Computer 18 In this experiment, you will use a Styrofoam-cup calorimeter to measure the heat released by three reactions. One of the reactions is the same as

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

By adding Equations 1, 2, and 3, the Overall Equation is obtained. Summation of their enthalpies gives the enthalpy of formation for MgO.

The standard enthalpy of formation of a compound, Hf o, is the heat change accompanying the formation of one mole of compound from the elements at standard state. The standard state of a substance is the

Calorimetry Experiments

Calorimetry Experiments Pre-Lab: Today s laboratory period will include a variety of activities designed to re-familiarize you with safe practices for chemistry laboratory, the space and equipment you

Chapter 7 Energy and Chemical Change: Breaking and Making Bonds

Multiple Choice Chapter 7 Energy and Chemical Change: Breaking and Making Bonds Section 7.1 1. Which one of the following is a unit of energy, but not an SI unit of energy? a. joule b. newton c. pascal

L q + w. CHM 1041 Thermochemistry Heats of Solution (Reaction) J. Bieber. Section: Date:

CHM 1041 Thermochemistry Heats of Solution (Reaction) J. Bieber Name: Partner: Section: Date: To study quantitatively the heat of solution when (1) a salt dissolves in water and (2) to study the heats

Heats of Transition, Heats of Reaction, Specific Heats, and Hess s Law

Heats of Transition, Heats of Reaction, Specific Heats, and Hess s Law GOAL AND OVERVIEW A simple calorimeter will be made and calibrated. It will be used to determine the heat of fusion of ice, the specific

DETERMINING THE ENTHALPY OF FORMATION OF CaCO 3

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

AP* Chemistry THERMOCHEMISTRY

AP* Chemistry THERMOCHEMISTRY Terms for you to learn that will make this unit understandable: Energy (E) the ability to do work or produce heat ; the sum of all potential and kinetic energy in a system

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

Thermodynamics. Energy can be used * to provide heat * for mechanical work * to produce electric work * to sustain life

Thermodynamics Energy can be used * to provide heat * for mechanical work * to produce electric work * to sustain life Thermodynamics is the study of the transformation of energy into heat and for doing

Thermochemistry: Enthalpy of Reaction Hess s Law

Thermochemistry: Enthalpy of Reaction Hess s Law Objective Demonstrate Hess s Law for determining the enthalpy of formation for MgO by measuring temperature change for several reactions. Introduction The

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

EXPERIMENT 9. Thermochemistry: Hess Law and the Heat of Formation of MgO

Outcomes EXPERIMENT 9 Thermochemistry: Hess Law and the Heat of Formation of MgO After completing this experiment, the student should be able to: 1. Differentiate between exothermic and endothermic reactions.

CHAPTER 6 THERMOCHEMISTRY

Chapter 6 Thermochemistry Page 1 CHAPTER 6 THERMOCHEMISTRY 6-1. The standard state of an element or compound is determined at a pressure of and a temperature of. (a) 760 atm, 0 o C (b) 1 mmhg, 273 o C

q = (mass) x (specific heat) x T = m c T (1)

Experiment: Heat Effects and Calorimetry Heat is a form of energy, sometimes called thermal energy, which can pass spontaneously from an object at a high temperature to an object at a lower temperature.

Chemistry 1215 Make up Lab Enthalpy of Neutralization

hemistry 1215 Make up Lab Enthalpy of Neutralization Objective In this experiment you will determine the molar enthalpy of neutralization of an acid. Introduction The study of energy and its transformations

Chapter 6: Thermochemistry (Chemical Energy) (Ch6 in Chang, Ch6 in Jespersen)

Chapter 6: Thermochemistry (Chemical Energy) (Ch6 in Chang, Ch6 in Jespersen) Energy is defined as the capacity to do work, or transfer heat. Work (w) - force (F) applied through a distance. Force - any

Determining the Effectiveness of Container Lids on Heat Absorption: Measuring Heat of Reaction for NaOH(aq) and HCl(aq)

SCHOLARS DAY REVIEW 27 SCHOLARS DAY REVIEW VOLUME 2 Determining the Effectiveness of Container Lids on Heat Absorption: Measuring Heat of Reaction for NaOH(aq) and HCl(aq) Christine L. Burton Faculty Sponsor:

Experiment 9 - Double Displacement Reactions

Experiment 9 - 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

EXPERIMENT #12 DOUBLE-REPLACEMENT REACTIONS

EXPERIMENT #12 DOUBLE-REPLACEMENT REACTIONS Purpose: 1. To study the most common type of double-replacement reactions. Principles: In double-replacement reactions, two compounds are involved in a reaction,

Chapter 5 Energy Relationships in Chemistry: Thermochemistry

Chapter 5 Energy Relationships in Chemistry: Thermochemistry In order to study thermochemical changes, we first have to define (a) system that specify part of the universe of interest to us. (b) surrounding

1. Read P. 368-375, P. 382-387 & P. 429-436; P. 375 # 1-11 & P. 389 # 1,7,9,12,15; P. 436 #1, 7, 8, 11

SCH3U- R.H.KING ACADEMY SOLUTION & ACID/BASE WORKSHEET Name: The importance of water - MAKING CONNECTION READING 1. Read P. 368-375, P. 382-387 & P. 429-436; P. 375 # 1-11 & P. 389 # 1,7,9,12,15; P. 436

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

Explorations in Thermodynamics: Calorimetry, Enthalpy & Heats of Reaction

Explorations in Thermodynamics: Calorimetry, Enthalpy & Heats of Reaction Dena K. Leggett, Ph.D. and Jon H. Hardesty, Ph.D. Collin County Community College Dept. of Chemistry 1. Introduction: One of the

Chemistry: Chemical Equations

Chemistry: Chemical Equations Write a balanced chemical equation for each word equation. Include the phase of each substance in the equation. Classify the reaction as synthesis, decomposition, single replacement,

The Mole Concept. A. Atomic Masses and Avogadro s Hypothesis

The Mole Concept A. Atomic Masses and Avogadro s Hypothesis 1. We have learned that compounds are made up of two or more different elements and that elements are composed of atoms. Therefore, compounds

Heat of Solution. Purpose To calculate the heat of solution for sodium hydroxide (NaOH) and ammonium nitrate (NH 4 NO 3 )

Heat of Solution Purpose To calculate the heat of solution for sodium hydroxide (NaOH) and ammonium nitrate (NH 4 NO 3 ) Background For a given solute, the heat of solution is the change in enerrgy that

STOICHIOMETRY STOICHIOMETRY. Measurements in Chemical Reactions. Mole-Mole Relationships. Mass-Mass Problem. Mole-Mole Relationships

STOICHIOMETRY STOICHIOMETRY The analysis of the quantities of substances in a chemical reaction. Stoichiometric calculations depend on the MOLE- MOLE relationships of substances. Measurements in Chemical

Thermodynamics- Chapter 19 Schedule and Notes

Thermodynamics- Chapter 19 Schedule and Notes Date Topics Video cast DUE Assignment during class time One Review of thermodynamics 1_thermo_review AND Review of thermo Wksheet 2.1ch19_intro Optional: 1sc_thermo

3A Energy. What is chemical energy?

3A Energy What is chemical energy? Chemical energy is a form of potential energy which is stored in chemical bonds. Chemical bonds are the attractive forces that bind atoms together. As a reaction takes

CHEMISTRY Practice exam #4 answer key October 16, 2007

CHEMISTRY 123-01 Practice exam #4 answer key October 16, 2007 1. An endothermic reaction causes the surroundings to a. warm up. b. become acidic. c. condense. 2. Which of the following is an example of

Thermochemistry Reading: Chapter 5 (omit 5.8) As you read ask yourself What is meant by the terms system and surroundings? How are they related to each other? How does energy get transferred between them?

Prelab attached (p 8-9) (g)! MgO (s) + heat (1)

CHEM 151 ENTHALPY OF FORMATION OF MgO FALL 2008 Fill-in Prelab attached (p 8-9) Stamp Here Name Partner Lecture instructor Date INTRODUCTION Chemical reactions either produce heat as they proceed (exothermic)

CHEMISTRY 110 Assignment #3 - answers 2011.

1. Titanium metal is used as a structural material in many high tech applications such as in jet engines. What is the specific heat of titanium in J/() if it takes 89.7 J to raise the temperature of a

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

Chapter 7: Chemical Equations. Name: Date: Period:

Chapter 7: Chemical Equations Name: Date: Period: 7-1 What is a chemical reaction? Read pages 232-237 a) Explain what a chemical reaction is. b) Distinguish between evidence that suggests a chemical reaction

Laboratory 6: Double Displacement Reactions

Introduction Double displacement reactions are among the most common of the simple chemical reactions to study and understand. We will explore the driving forces behind the chemical reactions, and use

6.1 Some basic principles

Ch 6 Thermochemistry: Energy Flow and Chemical Change 6.1 Forms of Energy and Their Interconversion 6.2 Enthalpy: Heats of Reaction and Chemical Change 6.3 Calorimetry: Laboratory Measurement of Heats

Chemistry Ch 15 (Solutions) Study Guide Introduction

Chemistry Ch 15 (Solutions) Study Guide Introduction Name: Note: a word marked (?) is a vocabulary word you should know the meaning of. A homogeneous (?) mixture, or, is a mixture in which the individual

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

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

CALORIMETRY AND HESS LAW: FINDING H o FOR THE COMBUSTION OF MAGNESIUM

Experiment 12J FV 7/16/06 CALORIMETRY AND HESS LAW: FINDING H o FOR THE COMBUSTION OF MAGNESIUM MATERIALS: Styrofoam coffee cup and lid, thermometer, magnetic stirrer, magnetic stir bar, 50-mL and 100-

Molecular Formula: Example

Molecular Formula: Example A compound is found to contain 85.63% C and 14.37% H by mass. In another experiment its molar mass is found to be 56.1 g/mol. What is its molecular formula? 1 CHAPTER 3 Chemical

CHEMISTRY 3310 PROBLEM SHEET #4

CHEMISTRY 3310 PROBLEM SHEET #4 1. The specific heats of a number of materials are listed below. Calculate the molar heat capacity for each. (a) gold, (b) rust (Fe 2 O 3 ) (c) sodium chloride 2. Calculate

Chemical calculations

Chemical calculations Stoichiometry refers to the quantities of material which react according to a balanced chemical equation. Compounds are formed when atoms combine in fixed proportions. E.g. 2Mg +

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

6/27/2014. Periodic Table of the ELEMENTS. Chemical REACTIONS you should know. Brief Review for 1311 Honors Exam 2

Brief Review for 3 Honors Exam 2 Chapter 2: Periodic Table I. Metals. Representative Metals Alkali Metals Group Alkaline Earth Metals. Group 2 2. Transition Metals II. Metalloids Chapter 3: All Chapter

Chapter Six. Energy Relationships in Chemical Reactions

Chapter Six Energy Relationships in Chemical Reactions 1 Energy (U): Capacity to Do Work Radiant energy Energy from the sun Nuclear energy Energy stored in the nucleus of an atom Thermal energy Energy

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

7 THERMOCHEMISTRY: HEAT OF REACTION

7 THERMOCHEMISTRY: HEAT OF REACTION Name: Date: Section: Objectives Measure the enthalpy of reaction for the decomposition of hydrogen peroxide Measure the heat capacity of a Styrofoam cup calorimeter

2 NO + O 2 2 NO 2 3/18/2014. iclicker Participation Question: A B C

Today: Stoichiometric Analysis: Gram to Gram Conversions: Use MOLAR MASS to get to moles Limiting Reagents: Method 1 Method 2 Actual Yield & Percent Yield Combustion Analysis Titrations Next Meeting Reading

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

Factors that Affect the Rate of Dissolving and Solubility

Dissolving Factors that Affect the Rate of Dissolving and Solubility One very important property of a solution is the rate of, or how quickly a solute dissolves in a solvent. When dissolving occurs, there

Procedure. Day 1 - Calibration of the Calorimeter. (Part I) The Heat Capacity of the Calorimeter.

Thermochemistry Experiment 10 Thermochemistry is the study of the heat energy involved in chemical reactions and changes of physical state. Heat energy is always spontaneously transferred from hotter to

Chemistry *P44269A0120* P44269A. Unit: KCH0/4CH0 Paper: 2C. Tuesday 9 June 2015 Afternoon Time: 1 hour. Instructions. Information.

Write your name here Surname Other names Pearson Edexcel Certificate Pearson Edexcel International GCSE Chemistry Unit: KCH0/4CH0 Paper: 2C Centre Number Candidate Number Tuesday 9 June 2015 Afternoon

The Physical Sciences Initiative. Chemistry Inservice D A T A L O G G I N G. Heat of Reaction. for. Graphic Calculator & Computer

The Physical Sciences Initiative Chemistry Inservice D A T A L O G G I N G Heat of Reaction for Graphic Calculator & Computer Nov 2001 1 Heat of Reaction. A Styrofoam cup calorimeter is used in this experiment

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

Chemical Reactions in Water Ron Robertson

Chemical Reactions in Water Ron Robertson r2 f:\files\courses\1110-20\2010 possible slides for web\waterchemtrans.doc Properties of Compounds in Water Electrolytes and nonelectrolytes Water soluble compounds

Chemical Reactions in Water

Chemical Reactions in Water Ron Robertson r2 f:\files\courses\1110-20\2010 possible slides for web\waterchemtrans.doc Acids, Bases and Salts Acids dissolve in water to give H + ions. These ions attach

Calculation of Molar Masses. Molar Mass. Solutions. Solutions

Molar Mass Molar mass = Mass in grams of one mole of any element, numerically equal to its atomic weight Molar mass of molecules can be determined from the chemical formula and molar masses of elements

TOPIC 10. CHEMICAL CALCULATIONS IV - solution stoichiometry.

TOPIC 10. CHEMICAL CALCULATIONS IV - solution stoichiometry. Calculations involving solutions. Frequently reactions occur between species which are present in solution. One type of chemical analysis called

Chapter 6 Quantities in Chemical Reactions

Chapter 6 Quantities in Chemical Reactions The Meaning of a Balanced Chemical Equation Mole-Mole Conversions Mass-Mass Conversions Limiting Reactants Percent Yield Energy Changes Copyright The McGraw-Hill

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

Chemical Equations and Calculations

Chemical Equations and Calculations A chemical equation is a shorthand way of indicating what is going on in a chemical reaction. We could do it the long way Two molecules of Hydrogen gas react with one

Chapter 5 Thermochemistry

Chapter 5 Thermochemistry 1. The ΔE of a system that releases 14.4 J of heat and does 4.8 J of work on the surroundings is J. (a). 19.2 J (b). 14.4 J (c). 4.8 J (d). - 19.2 J Explanation: The ΔE can be

Do Now CHEMICAL REACTIONS. Chemical Reaction. chemical reaction. Chemical Equations. Evidence

Do Now CHEMICAL REACTIONS What are some signs that a chemical change may have taken place? Where are the reactants and products in a reaction? What do they represent? Describe the law of conservation of

Chemical Equilibrium

1 Chemical Equilibrium Introduction: In many chemical reactions the reactants are not totally converted to products because of a reverse reaction. In reverse reactions, the products react to form the original

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

Experiment 1: Hot & Cold. Section 2, Group 3: (names omitted) Introduction by: Experimental by: Results by: Discussion by:

Experiment 1: Hot & Cold Section 2, Group 3: Introduction by: Experimental by: Results by: Discussion by: Introduction This report covers the investigation of temperature changes that were observed by

Chapter 3: Stoichiometry

Chapter 3: Stoichiometry Goal is to understand and become proficient at working with: 1. Avogadro's Number, molar mass and converting between mass and moles (REVIEW). 2. empirical formulas from analysis.