Enthalpy changes and calorimetry. Enthalpy changes in reactions Calorimetry and heat measurement Hess s Law Heats of formation
|
|
- Jason Carter
- 7 years ago
- Views:
Transcription
1 Enthalpy changes and calorimetry Enthalpy changes in reactions Calorimetry and heat measurement Hess s Law Heats of formation
2 Learning objectives Describe the standard state for thermodynamic functions Explain sign of enthalpy change for changes of state Calculate enthalpy changes for reactions Use specific heat and heat capacity in calorimetric problems Apply Hess law to calculations of enthalpy change Use standard heat of formation in calculations of enthalpy of reaction Use bond energies to estimate heats of reaction
3 The importance of state The heat change in a reaction will depend upon the states of the reactants and/or products States must be specified ΔH(1) = kj 1 2. C3H8( g) 5O2 ( g) 3CO2( g) 4H O( g) ΔH(2) = kj 2. C3H8( g) 5O2 ( g) 3CO2( g) 4H 2O( l) Additional heat is released in (2) because condensation of H 2 O releases 176 kj
4 Thermodynamic standard state Heat changes will also depend upon P and T The Standard State: Most stable form of a substance at 1 atm pressure and 25ºC(usually); 1 M concentration for solutions Conventionally, enthalpy change under standard conditions is represented by: ΔHº Any thermodynamic function referring to standard conditions is identified by º
5 Calculating ΔU from ΔHº Reaction between N 2 and H 2 at P = 40 atm and ΔV 1.12 L What is ΔU? N 2 (g) + 3H 2 (g) = 2NH 3 (g) ΔHº = kj U 92.2kJ ΔU = ΔH PΔV J 1kJ Latm 1000J 40x 1.12Latm 101 ΔU > ΔH Internal energy change is less negative by amount of work done by surroundings on compressing system 4.52kJ 87. kj U 92.2kJ 7
6 Enthalpies of change of state Conversion of a substance from one state to another involves heat input or output Heat is absorbed when breaking bonds Solid liquid gas Heat is released when making bonds Gas liquid solid Heat of fusion, vaporization etc. (formerly known as latent heats heat consumed with no change in T)
7 State functions ignore path Transition from solid to gas may lie through liquid phase... Or transition may be direct sublimation Enthalpy change is the same by either route ΔH subl = ΔH fusion + ΔH vap
8 Heat of reaction Enthalpy change for a reaction is commonly known as heat of reaction Exothermic refers to reaction where heat is given out by system (we warm our hands): ΔH < 0 Endothermic refers to reaction where heat is absorbed by system and surroundings get cool (hands get cold): ΔH > 0 NOTE SIGNS OF ΔH!
9 Calculations with ΔHº ΔHº may be quoted for a given equation or for one mole of a reactant or product Either way, it can be used to calculate the heat change for a given amount of substance
10 Example What is the heat evolved from the combustion of 15.5 g of C 3 H 8? C3H8( g) 5O2 ( g) 3CO2( g) 4H 2O( l)... H 2219kJ / mol Combustion of one mole of C 3 H 8 yields kj Molar mass of C 3 H 8 = 44.0 g/mol No moles in 15.5 g = 15.5/44.0 = mol Heat produced = x = kj
11 Worked example of heat of combustion
12 Calorimetry: the universe in the palm of your hand Heat change in process measured by temperature change of water in calorimeter (surroundings) Insulation confines heat exchange to process and calorimeter universe becomes the calorimeter
13 Heat capacity and specific heat Heat capacity, C: Heat required to raise temperature of body by 1ºC (extensive) C T Specific heat (capacity), c (σ): Heat required to raise 1 gram of the substance by 1ºC (intensive) q ct m q
14 Interactive calorimetry exercise Calculate some heat changes using virtual calorimeter Heats of solution
15 Constant pressure and constant volume Heat capacity can be defined at constant pressure and constant volume C P q T C V For solids and liquids they are similar For gases the values differ by R (the ideal gas constant): C P = C V + R q T
16 Molar heat capacity Related to specific heat (sometimes known as specific heat capacity) is the molar heat capacity, C m : the heat required to raise the temperature of 1 mole of a substance by 1ºC q Cm T moles
17 Some examples The heat capacity of water is much larger than many other substances Consequence of strong H-bonding Important consequences for climate, the quality of life, and life itself Substance S.H. (J/g o C) S,H. (J/mol o C) Air Aluminum Copper Gold Iron Mercury NaCl Water (s) Water (l)
18 Hess s law and the many Enthalpy being a state function means that enthalpy change for process is independent of pathway Hess s law states that: Overall enthalpy change for reaction equals sum of enthalpy changes for individual steps pathways
19 Application: determining ΔH for unknown process in terms of ΔH for known process Consider the reaction N 2 g) 3H 2( g) 2NH 3( g)... ( H Proceeds in two steps N N 2 g) 2H2( g) N2H4( g)... ( H 2 H 4 g) H 2( g) 2NH 3( g)... ( H ΔH 1 = ΔH 2 + ΔH 3 Reaction 1 is sum of reactions
20 Obtain ΔH 2 from ΔH 1 and ΔH 3 ΔH 2, which is hard to determine experimentally, is obtained using ΔH 1 and ΔH 3 ΔH 2 is endothermic, the others are exothermic
21 Combustion of CH 4 by alternate Route 1: ΔH 1 complete combustion to CO 2 Route 2: ΔH 2 + ΔH 3 intermediate product is CO Different pathways, same enthalpy ΔH 1 = ΔH 2 + ΔH 3 routes
22 Standard heats of formation Standard heat of formation, ΔH fº : The enthalpy change for the formation of 1 mole of a substance in its standard state from it constituent elements in their standard states ΔHº f for elements in most stable state is by definition 0
23 Reactions are often hypothetical ΔHº f (CH 4 ) is kj/mol although direct reaction between C and H 2 does not occur Important to know which is the standard state for any substance ΔHº f values are tabulated for many substances
24 Heats of reaction, ΔH fº, and Hess s law Application of ΔHº f to calculation of heats of reaction (ΔHº RXN ) For reaction: aa + bb = cc + dd Products reactants H o reaction c H ( C) d H ( D) a H ( A) b H ( B) o o o o f f f f
25 Worked example of heat of reaction H rxn H f ( CO2 ) H f ( H2O) H f ( C3H8)
26 Estimating ΔHº f using bond energies What if ΔHº f value(s) for reaction is (are) unknown? Estimate enthalpy change as difference between bonds broken (energy cost) and bonds made (energy gain) ΔHº RXN = D(reactant bonds) D(product bonds) COST (Bond energies are positive values) GAIN
27 Consider reaction: CH 4( g) 3Cl2( g) CHCl 3( g) 3HCl ( g) On reactant side: 3 C-H bonds and 3 Cl-Cl bonds are broken On product side: 3 C-Cl bonds and 3 H-Cl bonds are made 3D 3D 3D D H 3 ClCl CH Reaction is exothermic H Cl H-Cl bond is much stronger than Cl-Cl CCl 3x243 3x410 3x432 3x330kJ kj H 327
28 Worked example of heat of reaction from bond energies
29 More than enthalpy Some reactions are exothermic Some reactions are endothermic Both kinds of reaction can occur spontaneously. Or not. Why? The enthalpy is not the arbiter of spontaneity There is more to energy than heat We must also consider entropy Stay tuned for the Second Law
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 informationEnergy 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 informationThe first law: transformation of energy into heat and work. Chemical reactions can be used to provide heat and for doing work.
The first law: transformation of energy into heat and work Chemical reactions can be used to provide heat and for doing work. Compare fuel value of different compounds. What drives these reactions to proceed
More informationStandard 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 informationDETERMINING 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
More information1. 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 informationThermochemical 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 informationModule 5: Combustion Technology. Lecture 34: Calculation of calorific value of fuels
1 P age Module 5: Combustion Technology Lecture 34: Calculation of calorific value of fuels 2 P age Keywords : Gross calorific value, Net calorific value, enthalpy change, bomb calorimeter 5.3 Calculation
More informationThermochemistry. r2 d:\files\courses\1110-20\99heat&thermorans.doc. Ron Robertson
Thermochemistry r2 d:\files\courses\1110-20\99heat&thermorans.doc Ron Robertson I. What is Energy? A. Energy is a property of matter that allows work to be done B. Potential and Kinetic Potential energy
More informationSUPPLEMENTARY 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 informationChapter 18 Homework Answers
Chapter 18 Homework Answers 18.22. 18.24. 18.26. a. Since G RT lnk, as long as the temperature remains constant, the value of G also remains constant. b. In this case, G G + RT lnq. Since the reaction
More informationENTHALPY CHANGES FOR A CHEMICAL REACTION scaling a rxn up or down (proportionality) quantity 1 from rxn heat 1 from Δ r H. = 32.
CHEMISTRY 103 Help Sheet #10 Chapter 4 (Part II); Sections 4.6-4.10 Do the topics appropriate for your lecture Prepared by Dr. Tony Jacob http://www.chem.wisc.edu/areas/clc (Resource page) Nuggets: Enthalpy
More informationCHEM 36 General Chemistry EXAM #1 February 13, 2002
CHEM 36 General Chemistry EXAM #1 February 13, 2002 Name: Serkey, Anne INSTRUCTIONS: Read through the entire exam before you begin. Answer all of the questions. For questions involving calculations, show
More informationStates of Matter CHAPTER 10 REVIEW SECTION 1. Name Date Class. Answer the following questions in the space provided.
CHAPTER 10 REVIEW States of Matter SECTION 1 SHORT ANSWER Answer the following questions in the space provided. 1. Identify whether the descriptions below describe an ideal gas or a real gas. ideal gas
More informationUnit 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 informationSUGGESTION 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 informationUNIT 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 informationTransfer 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 information87 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 informationIntroductory 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 informationName Class Date. In the space provided, write the letter of the term or phrase that best completes each statement or best answers each question.
Assessment Chapter Test A Chapter: States of Matter In the space provided, write the letter of the term or phrase that best completes each statement or best answers each question. 1. The kinetic-molecular
More informationEnthalpy 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 information11 Thermodynamics and Thermochemistry
Copyright ç 1996 Richard Hochstim. All rights reserved. Terms of use.» 37 11 Thermodynamics and Thermochemistry Thermodynamics is the study of heat, and how heat can be interconverted into other energy
More informationThermodynamics. 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 informationMr. 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 informationChapter 6 Thermodynamics: The First Law
Key Concepts 6.1 Systems Chapter 6 Thermodynamics: The First Law Systems, States, and Energy (Sections 6.1 6.8) thermodynamics, statistical thermodynamics, system, surroundings, open system, closed system,
More informationUnit 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 informationChemistry 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 informationChem 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 informationTest 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 information1 Exercise 2.19a pg 86
In this solution set, an underline is used to show the last significant digit of numbers. For instance in x = 2.51693 the 2,5,1, and 6 are all significant. Digits to the right of the underlined digit,
More informationIntermolecular Forces
Intermolecular Forces: Introduction Intermolecular Forces Forces between separate molecules and dissolved ions (not bonds) Van der Waals Forces 15% as strong as covalent or ionic bonds Chapter 11 Intermolecular
More informationwww.chemsheets.co.uk 17-Jul-12 Chemsheets A2 033 1
www.chemsheets.co.uk 17-Jul-12 Chemsheets A2 033 1 AS THERMODYNAMICS REVISION What is enthalpy? It is a measure of the heat content of a substance Enthalpy change ( H) = Change in heat content at constant
More information10 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 informationHeat 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
More informationDetermination 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 informationChemistry 11 Some Study Materials for the Final Exam
Chemistry 11 Some Study Materials for the Final Exam Prefix Abbreviation Exponent giga G 10 9 mega M 10 6 kilo k 10 3 hecto h 10 2 deca da 10 1 deci d 10-1 centi c 10-2 milli m 10-3 micro µ 10-6 nano n
More informationMULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
Exam Name MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Given: 4 NO2(g) + O2(g) 2 N2O5(g) ΔH = -110.2 kj find ΔH for N2O5(g) 2 NO2(g) + 1/2 O2(g).
More informationChemical 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 informationChapter 5 Principles of Chemical Reactivity: Energy and Chemical Reactions
PRACTICING SKILLS Energy Chapter 5 Principles of Chemical Reactivity: 1. To move the lever, one uses mechanical energy. The energy resulting is manifest in electrical energy (which produces light); thermal
More informationReading: Moore chapter 18, sections 18.6-18.11 Questions for Review and Thought: 62, 69, 71, 73, 78, 83, 99, 102.
Thermodynamics 2: Gibbs Free Energy and Equilibrium Reading: Moore chapter 18, sections 18.6-18.11 Questions for Review and Thought: 62, 69, 71, 73, 78, 83, 99, 102. Key Concepts and skills: definitions
More informationThermochemistry: 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 informationHEAT 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 informationChapter 13. Properties of Solutions
Sample Exercise 13.1 (p. 534) By the process illustrated below, water vapor reacts with excess solid sodium sulfate to form the hydrated form of the salt. The chemical reaction is Na 2 SO 4(s) + 10 H 2
More informationWhy? Intermolecular Forces. Intermolecular Forces. Chapter 12 IM Forces and Liquids. Covalent Bonding Forces for Comparison of Magnitude
1 Why? Chapter 1 Intermolecular Forces and Liquids Why is water usually a liquid and not a gas? Why does liquid water boil at such a high temperature for such a small molecule? Why does ice float on water?
More information4. Using the data from Handout 5, what is the standard enthalpy of formation of BaO (s)? What does this mean?
HOMEWORK 3A 1. In each of the following pairs, tell which has the higher entropy. (a) One mole of liquid water or one mole of water vapor (b) One mole of dry ice or one mole of carbon dioxide at 1 atm
More informationThermochemistry 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 informationFORMA is EXAM I, VERSION 1 (v1) Name
FORMA is EXAM I, VERSION 1 (v1) Name 1. DO NOT TURN THIS PAGE UNTIL DIRECTED TO DO SO. 2. These tests are machine graded; therefore, be sure to use a No. 1 or 2 pencil for marking the answer sheets. 3.
More informationThermodynamics Worksheet I also highly recommend Worksheets 13 and 14 in the Lab Manual
Thermodynamics Worksheet I also highly recommend Worksheets 13 and 14 in the Lab Manual 1. Predict the sign of entropy change in the following processes a) The process of carbonating water to make a soda
More informationTest 5 Review questions. 1. As ice cools from 273 K to 263 K, the average kinetic energy of its molecules will
Name: Thursday, December 13, 2007 Test 5 Review questions 1. As ice cools from 273 K to 263 K, the average kinetic energy of its molecules will 1. decrease 2. increase 3. remain the same 2. The graph below
More informationChapter 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 information1. 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 informationEnthalpy 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 informationFinal 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 informationvap H = RT 1T 2 = 30.850 kj mol 1 100 kpa = 341 K
Thermodynamics: Examples for chapter 6. 1. The boiling point of hexane at 1 atm is 68.7 C. What is the boiling point at 1 bar? The vapor pressure of hexane at 49.6 C is 53.32 kpa. Assume that the vapor
More informationCHEM 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 informationSample Problem: STOICHIOMETRY and percent yield calculations. How much H 2 O will be formed if 454 g of. decomposes? NH 4 NO 3 N 2 O + 2 H 2 O
STOICHIOMETRY and percent yield calculations 1 Steps for solving Stoichiometric Problems 2 Step 1 Write the balanced equation for the reaction. Step 2 Identify your known and unknown quantities. Step 3
More informationPREPARATION 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 informationLiquid 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 informationDetermination 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 information7. 1.00 atm = 760 torr = 760 mm Hg = 101.325 kpa = 14.70 psi. = 0.446 atm. = 0.993 atm. = 107 kpa 760 torr 1 atm 760 mm Hg = 790.
CHATER 3. The atmosphere is a homogeneous mixture (a solution) of gases.. Solids and liquids have essentially fixed volumes and are not able to be compressed easily. have volumes that depend on their conditions,
More informationPhysical and Chemical Properties of Matter
Physical and Chemical Properties of Matter What is matter? Anything that has mass and takes up space Chemical or Physical Property? Physical properties of matter: characteristics that can be observed or
More informationEXPERIMENT 15: Ideal Gas Law: Molecular Weight of a Vapor
EXPERIMENT 15: Ideal Gas Law: Molecular Weight of a Vapor Purpose: In this experiment you will use the ideal gas law to calculate the molecular weight of a volatile liquid compound by measuring the mass,
More information48 Practice Problems for Ch. 17 - Chem 1C - Joseph
48 Practice Problems for Ch. 17 - Chem 1C - Joseph 1. Which of the following concentration measures will change in value as the temperature of a solution changes? A) mass percent B) mole fraction C) molality
More informationIB 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 informationThermodynamics and Equilibrium
Chapter 19 Thermodynamics and Equilibrium Concept Check 19.1 You have a sample of 1.0 mg of solid iodine at room temperature. Later, you notice that the iodine has sublimed (passed into the vapor state).
More informationExperiment 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 informationthermometer 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 informationBomb Calorimetry. Electrical leads. Stirrer
Bomb Calorimetry Stirrer Electrical leads Oxygen inlet valve Bomb Fuse Calorimeter Outer jacket Not shown: heating and cooling system for outer jacket, and controls that keep the outer jacket at the same
More informationOther 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 informationINTI COLLEGE MALAYSIA A? LEVEL PROGRAMME CHM 111: CHEMISTRY MOCK EXAMINATION: DECEMBER 2000 SESSION. 37 74 20 40 60 80 m/e
CHM111(M)/Page 1 of 5 INTI COLLEGE MALAYSIA A? LEVEL PROGRAMME CHM 111: CHEMISTRY MOCK EXAMINATION: DECEMBER 2000 SESSION SECTION A Answer ALL EIGHT questions. (52 marks) 1. The following is the mass spectrum
More informationProblem Solving. Stoichiometry of Gases
Skills Worksheet Problem Solving Stoichiometry of Gases Now that you have worked with relationships among moles, mass, and volumes of gases, you can easily put these to work in stoichiometry calculations.
More information2. 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 informationChemistry: 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,
More informationType: Single Date: Homework: READ 12.8, Do CONCEPT Q. # (14) Do PROBLEMS (40, 52, 81) Ch. 12
Type: Single Date: Objective: Latent Heat Homework: READ 12.8, Do CONCEPT Q. # (14) Do PROBLEMS (40, 52, 81) Ch. 12 AP Physics B Date: Mr. Mirro Heat and Phase Change When bodies are heated or cooled their
More informationExp 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 informationProblem Set 1 3.20 MIT Professor Gerbrand Ceder Fall 2003
LEVEL 1 PROBLEMS Problem Set 1 3.0 MIT Professor Gerbrand Ceder Fall 003 Problem 1.1 The internal energy per kg for a certain gas is given by U = 0. 17 T + C where U is in kj/kg, T is in Kelvin, and C
More informationCHEMISTRY STANDARDS BASED RUBRIC ATOMIC STRUCTURE AND BONDING
CHEMISTRY STANDARDS BASED RUBRIC ATOMIC STRUCTURE AND BONDING Essential Standard: STUDENTS WILL UNDERSTAND THAT THE PROPERTIES OF MATTER AND THEIR INTERACTIONS ARE A CONSEQUENCE OF THE STRUCTURE OF MATTER,
More informationPV (0.775 atm)(0.0854 L) n = = = 0.00264 mol RT -1-1
catalyst 2 5 g ¾¾¾¾ 2 4 g 2 g DH298 = rxn DS298 C H OH( ) C H ( ) + H O( ) 45.5 kj/mol ; = 126 J/(K mol ) ethanol ethene water rxn 1 atm 760 torr PV (0.775 atm)(0.0854 L) n = = = 0.00264 mol RT -1-1 (0.08206
More informationChemistry 110 Lecture Unit 5 Chapter 11-GASES
Chemistry 110 Lecture Unit 5 Chapter 11-GASES I. PROPERITIES OF GASES A. Gases have an indefinite shape. B. Gases have a low density C. Gases are very compressible D. Gases exert pressure equally in all
More informationChapter 4 Practice Quiz
Chapter 4 Practice Quiz 1. Label each box with the appropriate state of matter. A) I: Gas II: Liquid III: Solid B) I: Liquid II: Solid III: Gas C) I: Solid II: Liquid III: Gas D) I: Gas II: Solid III:
More informationChem 420/523 Chemical Thermodynamics Homework Assignment # 6
Chem 420/523 Chemical hermodynamics Homework Assignment # 6 1. * Solid monoclinic sulfur (S α ) spontaneously converts to solid rhombic sulfur (S β ) at 298.15 K and 0.101 MPa pressure. For the conversion
More informationSpring 2009. kj mol 125 0-229 -92. H f. H rxn = Σ H f (products) - Σ H f (reactants)
Spring 2009 2. The reaction of an elemental halogen with an alkane is a very common reaction. The reaction between chlorine and butane is provided below. (NOTE: Questions a d and f pertain to this reaction.)
More informationA n = 2 to n = 1. B n = 3 to n = 1. C n = 4 to n = 2. D n = 5 to n = 2
North arolina Testing Program EO hemistry Sample Items Goal 4 1. onsider the spectrum for the hydrogen atom. In which situation will light be produced? 3. Which color of light would a hydrogen atom emit
More informationProblem Set 3 Solutions
Chemistry 360 Dr Jean M Standard Problem Set 3 Solutions 1 (a) One mole of an ideal gas at 98 K is expanded reversibly and isothermally from 10 L to 10 L Determine the amount of work in Joules We start
More informationESSAY. Write your answer in the space provided or on a separate sheet of paper.
Test 1 General Chemistry CH116 Summer, 2012 University of Massachusetts, Boston Name ESSAY. Write your answer in the space provided or on a separate sheet of paper. 1) Sodium hydride reacts with excess
More informationElement of same atomic number, but different atomic mass o Example: Hydrogen
Atomic mass: p + = protons; e - = electrons; n 0 = neutrons p + + n 0 = atomic mass o For carbon-12, 6p + + 6n 0 = atomic mass of 12.0 o For chlorine-35, 17p + + 18n 0 = atomic mass of 35.0 atomic mass
More informationFREE RADICAL REACTIONS A STUDENT WHO HAS MASTERED THE MATERIAL IN THIS SECTION SHOULD BE ABLE TO:
FREE RADICAL REACTIONS A STUDENT WO AS MASTERED TE MATERIAL IN TIS SECTION SOULD BE ABLE TO: 1. Define, recognize, and give examples of: homolytic cleavage (homolysis), heterolytic cleavage, free radical,
More informationChem 338 Homework Set #5 solutions October 10, 2001 From Atkins: 5.2, 5.9, 5.12, 5.13, 5.15, 5.17, 5.21
Chem 8 Homework Set #5 solutions October 10, 2001 From Atkins: 5.2, 5.9, 5.12, 5.1, 5.15, 5.17, 5.21 5.2) The density of rhombic sulfur is 2.070 g cm - and that of monoclinic sulfur is 1.957 g cm -. Can
More informationAdiabatic 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 informationChemical 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 informationFUNDAMENTALS OF ENGINEERING THERMODYNAMICS
FUNDAMENTALS OF ENGINEERING THERMODYNAMICS System: Quantity of matter (constant mass) or region in space (constant volume) chosen for study. Closed system: Can exchange energy but not mass; mass is constant
More informationMULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
General Chemistry PHS 1015 Practice Exam 4 Name MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Which of the following statements about pressure
More informationHow 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 informationMULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
A.P. Chemistry Practice Test: Ch. 11, Solutions Name MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Formation of solutions where the process is
More informationGibbs Free Energy and Chemical Potential. NC State University
Chemistry 433 Lecture 14 Gibbs Free Energy and Chemical Potential NC State University The internal energy expressed in terms of its natural variables We can use the combination of the first and second
More informationIn the box below, draw the Lewis electron-dot structure for the compound formed from magnesium and oxygen. [Include any charges or partial charges.
Name: 1) Which molecule is nonpolar and has a symmetrical shape? A) NH3 B) H2O C) HCl D) CH4 7222-1 - Page 1 2) When ammonium chloride crystals are dissolved in water, the temperature of the water decreases.
More informationThe value of a state function is independent of the history of the system.
1 THERMODYNAMICS - The study of energy in matter - Thermodynamics allows us to predict whether a chemical reaction occurs or not. - Thermodynamics tells us nothing about how fast a reaction occurs. - i.
More informationAP CHEMISTRY 2007 SCORING GUIDELINES. Question 2
AP CHEMISTRY 2007 SCORING GUIDELINES Question 2 N 2 (g) + 3 F 2 (g) 2 NF 3 (g) ΔH 298 = 264 kj mol 1 ; ΔS 298 = 278 J K 1 mol 1 The following questions relate to the synthesis reaction represented by the
More informationChemistry 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