I. CALORIMETRY CALORIMETRY
|
|
- Cory Ross
- 7 years ago
- Views:
Transcription
1 CALORIMETRY I. CALORIMETRY If the process (e.g. chemical reaction, phase conversion) requires heat to proceed, it is said to be endothermic. For endothermic process, q > 0. If the process (e.g. chemical reaction, phase conversion) evolves heat, it is said to be exothermic. For exothermic process, q < 0. Letter "q" denotes the heat flow between surroundings and the system. We often need to know the magnitude and direction of the heat flow for a process. The method by which the heat flow is measure is termed calorimetry. If you would like to measure the heat flow in a process, you must have an isolated vessel called a calorimeter. The most commonly used calorimeters base on so called Dewar s vessel. However one can use as simple systems as e.g. two Styrofoam coffee cups placed inside the other and covered with a lid. In all our experiments the calorimeter will be filled with water the temperature of which will be measured. The calorimeter and water are called surroundings and the substance/s undergoing an investigated process is/are called system. The specific heat (C) of a substance is that amount of heat which is required to increase the temperature of one gram of a substance by one Kelvin (or one degree Celsius). The heat capacity of the calorimeter (K), sometimes denoted as calorimeter constant, is that amount of heat which is required to increase the temperature of calorimeter by one Kelvin (or one degree Celsius). Note the difference between specific heat and heat capacity. We cannot measure heat directly. Instead, we measure the change in temperature of the water. The equation which relates heat flow, temperature change and specific heat is: Where m is the mass of the substance, C is the specific heat, and ΔT is the change in temperature (Tfinal-Tinitial). This equation can be used to calculate the amount of heat gained or lost by water on proceeding the investigated process. For endothermic process, q > 0:
2 Because the calorimeter is a closed system, all the heat gained by the changing system has to be lost by water. Therefore we can write the following equation: For exothermic process, q < 0: Because the calorimeter is a closed system, all the heat evolved by the changing system has to be gained by water. Therefore we can write the following equation: These equations imply that the heat lost/gained by the system is equal and opposite to the heat gained/lost by the water. One should interpret the negative sign to mean "opposite to". If we take into account that the real calorimeter is a setup consisting of dewar vessel, water, stirrer, termometer, the product m w C w in equations (3) and (4) should be replaced with the heat volume of calorimeter (K), i.e.: Equations (4a) and (5a) can be used to calculate heat lost/gained by the system (q process ) when we know the values of K and ΔT w or to calculate K, when we know the values of q process and ΔT w.
3 I.A. HEAT OF MELTING OF ICE Purpose: to learn the principles of calorimetry measurements, to determine the heat of melting of ice Procedure: 1. Weigh the empty Dewar vessel. 2. Fill the Dewar vessel with 50.0 ml of ~30 C water and weigh the vessel. Record the mass. 2. Measure and record the initial temperature of the water. 3. Add 2-3 ice cubes to the water. Stir gently with the temperature probe. Before the ice is completely melted, add another ice cube. 4. Continue adding ice cubes in this manner until the temperature reaches a plateau. Record the final temperature. 5. Carefully pull out the remaining ice cubes, allow the water to drop back into the vessel. 6. Weigh the vessel and record the mass. Calculations: 1. Find the mass of water originally in the cup. 2. Calculate the amount of heat the water gave to the ice cubes. Use the mass of water and the change in temperature. 3. Calculate the mass of ice which melted. 4. The amount of heat released by the water (and calculated in step 2) is equal to the amount of heat absorbed by the ice. Knowing this and the mass of the ice which melted, calculate the heat of melting of ice in units of J/g. Recalculate it to kj/mole of ice. 4. Find the error in %. Include in the introduction the definition of heat, the definition of heat of melting, describe the calorimetry and how it works. Give the accepted values for the heat of melting of ice, in both kj/mole and J/g. Make sure all equations used are clearly shown in your calculations.
4 I.B. HEAT OF SOLUTION OF A SOLID Purpose: to learn the principles of calorimetric measurements, to observe the dependence of the heat of solution on the concentration of the solution formed. The process of solid dissolution in water is always associated with energy change (heat). The dissolving process itself is a two-step process. The first step, that of breaking down the solid crystal, is endothermic. The second step, that of hydrating the individual particles released into the solvent, is exothermic. For an ionic compound, ionic bonds are broken while ion-dipole interactions appear and the ionic compound dissociates into ions, negative and positive ones. Ion-dipole interactions appear when the slightly positive hydrogen atoms of water molecule are attracted to the negative ions, and the slightly negative oxygen atoms of the water molecule are attracted to the positive ions. We talk about the hydration of ions. The overall heat of solution depends on the relative amounts of energy involved in the two individual steps. Hydration of ions involves a complex redirection of forces of attraction and repulsion. Before the solution forms, water molecules are attracted only to each other; and positive and negative ions have only each other in the crystal to be attracted to. In the solution, the ions have water molecules to take the places of their oppositely charged counterparts; and water molecules find ions more attractive then even other water molecules. In this experiment, you will determine the heats of solution for the dissolving of the same amount of a salt (e.g. ammonium nitrate, sodium acetate, sodium thiosulphate) in different amounts of water using a Dewar vessel as a calorimeter. Procedure: 1. Accurately weigh a sample of solid salt of approximately 5 grams. 2. Add exactly 500 ml of water to the Dewar vessel. 3. Stir the water briefly with the stirrer and start recording the temperature every 30 s. 4. Dissolve the solid in the water, stirring continuously, and continue recording the temperature. 5. Rinse out the vessel, dry it thoroughly, and repeat the experiment twice adding 250 ml of water.
5 Calculations: 1. Calculate the following for each part of the experiment. a) the temperature change of the water. (Hint: make a plot of temperature versus time of observation.) b) the quantity of heat gained (or given off) by the water during the dissolving, K=2,5 kj/deg. c) the number of moles of salt used. e) the molar heat of solution, i.e. the quantity of heat involved per mole of salt dissolved. 2. Find the accepted values for the molar heats of solution for these solids in a chemistry handbook, and calculate the percentage error of your experimental values. Observe whether the numbers given in a handbook concern the molar ratio of salt and water. Questions: 1. Write an equation for the dissolving process for each salt adding the heat term to each equation. 2. Describe each step of the two-step process of dissolution using both words and a diagram. Designate each step as endothermic or exothermic. 3. Which of these individual steps shows the higher absolute value?
6 I.C. HEAT OF NEUTRALIZATION REACTION The neutralization reaction The reaction of sulfuric acid with sodium base can be written as follows: or in an ionic form: It appears that the reaction proceeds between hydrogen cations and hydroxyl anions and results in the formation of water. Definition: the neutralization reaction of strong acid with strong base is the reaction of hydrated hydrogen cations with hydrated hydroxyl anions resulting in the formation of water: Heat of this reaction does not depend on the type of acid or base and equals kj per mole of water formed. Procedure: 1. Fill a glass ampoule with ca. 3 g of sulfuric acid (you should know the exact mass of acid). Ask TA for assistance. 2. Calculate what volume of NaOH water solution (20% w/w) is needed to neutralize the amount of acid you have in an ampoule. Ask TA for the acceptance of your calculations. 3. Place the calculated volume (increased by 30%) of NaOH solution into an Dewar vessel and add water so that the final volume of the obtained solution would be exactly 500 ml. 4. Mount the ampoule containing sulfuric acid in the holder provided with the calorimter setup. Connect stirrer to the electric engine. Place properly the temperature probe in Dewar vessel. 5. Stir the water briefly and start recording the temperature every 30 s. 6. Allow sulfuric acid to dissolve in the solution by breaking smoothly the glass ampoule. Do not stop stirring and continue recording the temperature until its value reaches plateau.
7 CALORIMETRY 7. Dismount carefully the calorimeter setup. Rinse Dewar vessel with water. Rinse the broken ampoule with water and give it back to the TA. Calculations: 1. Make a plot of temperature versus time and read out the temperature change (increase). 2. Calculate the heat flow observed on dissolving sulfuric acid in the water solution of sodium base. 3. Note that the observed heat flow results from the two processe taking place simultaneousely in an Dewar vessel. They are: (i) dissolution od sulfuric acid in water and (ii) neutralization reaction: therefore 4. Find the heat of sulfuric acid solution in water in a chemical handbook. Calculate the observed heat of neutralization taking the heat capacity of the calorimetric setup a 2.5kJ/deg. Hint: heat values shown in tables refer to one mole of sulfuric acid, while you have used much lower amount. 5. Calculate the heat of neutralization for one mole of water formed. Hint: From one mole of fully neutralized sulfuric acid two moles of water are formed. 6. Compare the obtained molar value of the heat of neutralization with accepted value. Comment possible differences.
8 I.D. DETERMINING THE HEAT CAPACITY OF CALORIMETER Purpose: to learn the principles of calorimetry measurements, to determine the heat capacity of calorimeter, i.e to calibrate the calorimeter Procedure: 1. Fill a glass ampoule with ca. 2,5-3 g of sulfuric acid (you should know the exact mass of acid). Ask TA for assistance. 2. Add exactly 500 ml of water to the Dewar vessel. 3. Place the ampoule, stirrer and thermometer probe on their places. 4. Stir the water briefly with the stirrer and start recording the temperature every 30 s. 5. Allow acid to dissolve in water by gentle breaking the glass ampoule. Continue recording temperature until its value reaches plateau. 6. Dismount carefully the calorimeter setup. Rinse Dewar vessel with water. Rinse the broken ampoule with water and give it back to the TA. 7. Repeat steps 2 6 taking 5-6 g of sulfuric acid. Calculations: 1. Make a plot of temperature versus time and read out the temperature change (increase). 2. Find the heat of sulfuric acid solution in water in a chemical handbook and calculate the heat loss (q process ) during the process of acid dissolution in water. Hint: heat values shown in tables refer to one mole of sulfuric acid, while you have used much lower amount 3. Calculate the heat capacity of the calorimeter. 4. Compare the result of the two experiments. Does the heat capacity of the calorimeter depend on the amount of acid taken? Haw could you easily change the heat capacity of your calorimeter?
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 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 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 informationph: Measurement and Uses
ph: Measurement and Uses One of the most important properties of aqueous solutions is the concentration of hydrogen ion. The concentration of H + (or H 3 O + ) affects the solubility of inorganic and organic
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 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 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 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 informationScience 20. Unit A: Chemical Change. Assignment Booklet A1
Science 20 Unit A: Chemical Change Assignment Booklet A FOR TEACHER S USE ONLY Summary Teacher s Comments Chapter Assignment Total Possible Marks 79 Your Mark Science 20 Unit A: Chemical Change Assignment
More informationBomb 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 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 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 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 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 informationChem101: General Chemistry Lecture 9 Acids and Bases
: General Chemistry Lecture 9 Acids and Bases I. Introduction A. In chemistry, and particularly biochemistry, water is the most common solvent 1. In studying acids and bases we are going to see that water
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 informationThe Mole Concept. The Mole. Masses of molecules
The Mole Concept Ron Robertson r2 c:\files\courses\1110-20\2010 final slides for web\mole concept.docx The Mole The mole is a unit of measurement equal to 6.022 x 10 23 things (to 4 sf) just like there
More 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 informationEXPERIMENT 12 A SOLUBILITY PRODUCT CONSTANT
PURPOSE: 1. To determine experimentally the molar solubility of potassium acid tartrate in water and in a solution of potassium nitrate. 2. To examine the effect of a common ion on the solubility of slightly
More informationSOLUBILITY OF A SALT IN WATER AT VARIOUS TEMPERATURES LAB
SOLUBILITY OF A SALT IN WATER AT VARIOUS TEMPERATURES LAB Purpose: Most ionic compounds are considered by chemists to be salts and many of these are water soluble. In this lab, you will determine the solubility,
More informationFreezing Point Depression: Why Don t Oceans Freeze? Teacher Advanced Version
Freezing Point Depression: Why Don t Oceans Freeze? Teacher Advanced Version Freezing point depression describes the process where the temperature at which a liquid freezes is lowered by adding another
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 informationThe 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 informationDetermining the Identity of an Unknown Weak Acid
Purpose The purpose of this experiment is to observe and measure a weak acid neutralization and determine the identity of an unknown acid by titration. Introduction The purpose of this exercise is to identify
More informationThe Mole Concept and Atoms
Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Chapter 4 24 September 2013 Calculations and the Chemical Equation The Mole Concept and Atoms Atoms are exceedingly
More informationThe 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 informationMOLARITY = (moles solute) / (vol.solution in liter units)
CHEM 101/105 Stoichiometry, as applied to Aqueous Solutions containing Ionic Solutes Lect-05 MOLES - a quantity of substance. Quantities of substances can be expressed as masses, as numbers, or as moles.
More 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 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 informationNeutralization Reactions. Evaluation copy
Neutralization Reactions Computer 6 If an acid is added to a base, a chemical reaction called neutralization occurs. An example is the reaction between nitric acid, HNO 3, and the base potassium hydroxide,
More informationCalculation 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
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 informationSUPPLEMENTARY MATERIAL
SUPPLEMENTARY MATERIAL (Student Instructions) Determination of the Formula of a Hydrate A Greener Approach Objectives To experimentally determine the formula of a hydrate salt. To learn to think in terms
More informationACID-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 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 informationChemical Composition. Introductory Chemistry: A Foundation FOURTH EDITION. Atomic Masses. Atomic Masses. Atomic Masses. Chapter 8
Introductory Chemistry: A Foundation FOURTH EDITION by Steven S. Zumdahl University of Illinois Chemical Composition Chapter 8 1 2 Atomic Masses Balanced equation tells us the relative numbers of molecules
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 informationNaCl Lattice Science Activities
NaCl Lattice Science Activities STEM: The Science of Salt Using a Salt Lattice Model Teacher Notes Science Activities A Guided-Inquiry Approach Using the 3D Molecular Designs NaCl Lattice Model Classroom
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 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 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 informationIB 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 informationCHEMICAL DETERMINATION OF EVERYDAY HOUSEHOLD CHEMICALS
CHEMICAL DETERMINATION OF EVERYDAY HOUSEHOLD CHEMICALS Purpose: It is important for chemists to be able to determine the composition of unknown chemicals. This can often be done by way of chemical tests.
More informationDescription of the Mole Concept:
Description of the Mole Concept: Suppose you were sent into the store to buy 36 eggs. When you picked them up you would get 3 boxes, each containing 12 eggs. You just used a mathematical device, called
More informationChapter 5 Student Reading
Chapter 5 Student Reading THE POLARITY OF THE WATER MOLECULE Wonderful water Water is an amazing substance. We drink it, cook and wash with it, swim and play in it, and use it for lots of other purposes.
More informationChapter 5, Lesson 3 Why Does Water Dissolve Salt?
Chapter 5, Lesson 3 Why Does Water Dissolve Salt? Key Concepts The polarity of water molecules enables water to dissolve many ionically bonded substances. Salt (sodium chloride) is made from positive sodium
More informationDesalination of Sea Water E7-1
Experiment 7 Desalination of Sea Water E7-1 E7-2 The Task The goal of this experiment is to investigate the nature and some properties of sea water. Skills At the end of the laboratory session you should
More informationChemistry 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
More informationChemistry. The student will be able to identify and apply basic safety procedures and identify basic equipment.
Chemistry UNIT I: Introduction to Chemistry The student will be able to describe what chemistry is and its scope. a. Define chemistry. b. Explain that chemistry overlaps many other areas of science. The
More informationTo measure the solubility of a salt in water over a range of temperatures and to construct a graph representing the salt solubility.
THE SOLUBILITY OF A SALT IN WATER AT VARIOUS TEMPERATURES 2007, 1995, 1991 by David A. Katz. All rights reserved. Permission for academic use provided the original copyright is included. OBJECTIVE To measure
More informationstoichiometry = the numerical relationships between chemical amounts in a reaction.
1 REACTIONS AND YIELD ANSWERS stoichiometry = the numerical relationships between chemical amounts in a reaction. 2C 8 H 18 (l) + 25O 2 16CO 2 (g) + 18H 2 O(g) From the equation, 16 moles of CO 2 (a greenhouse
More informationChemical Formulas, Equations, and Reactions Test Pre-AP Write all answers on your answer document.
Name: Period: Chemical Formulas, Equations, and Reactions Test Pre-AP Write all answers on your answer document. 1. Which of the following is a NOT a physical property of hydrogen? A. It is gas C. It is
More 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 informationHands-On Labs SM-1 Lab Manual
EXPERIMENT 4: Separation of a Mixture of Solids Read the entire experiment and organize time, materials, and work space before beginning. Remember to review the safety sections and wear goggles when appropriate.
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 informationEXPERIMENT 9 (Organic Chemistry II) Pahlavan - Cherif Synthesis of Aspirin - Esterification
EXPERIMENT 9 (rganic hemistry II) Pahlavan - herif Materials Hot plate 125-mL Erlenmeyer flask Melting point capillaries Melting point apparatus Büchner funnel 400-mL beaker Stirring rod hemicals Salicylic
More informationGeneral 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 informationChapter 8 How to Do Chemical Calculations
Chapter 8 How to Do Chemical Calculations Chemistry is both a qualitative and a quantitative science. In the laboratory, it is important to be able to measure quantities of chemical substances and, as
More informationPre-Lab Notebook Content: Your notebook should include the title, date, purpose, procedure; data tables.
Determination of Molar Mass by Freezing Point Depression M. Burkart & M. Kim Experimental Notes: Students work in pairs. Safety: Goggles and closed shoes must be worn. Dispose of all chemical in the plastic
More informationWhat s in a Mole? Molar Mass
LESSON 10 What s in a Mole? Molar Mass OVERVIEW Key Ideas Lesson Type Lab: Groups of 4 Chemists compare moles of substances rather than masses because moles are a way of counting atoms. When considering
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 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 informationApparatus 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 informationChemistry Diagnostic Questions
Chemistry Diagnostic Questions Answer these 40 multiple choice questions and then check your answers, located at the end of this document. If you correctly answered less than 25 questions, you need to
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 informationEXPERIMENT 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 informationProperties of Hydrates Prelab. 3. Give the chemical formula for copper(ii) nitrate pentahydrate.
Properties of Hydrates Prelab Name Total /10 SHOW ALL WORK NO WORK = NO CREDIT 1. What is the purpose of this experiment?. What is the definition of a hydrate? 3. Give the chemical formula for copper(ii)
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 informationChemical 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 informationChem 1B Saddleback College Dr. White 1. Experiment 8 Titration Curve for a Monoprotic Acid
Chem 1B Saddleback College Dr. White 1 Experiment 8 Titration Curve for a Monoprotic Acid Objectives To learn the difference between titration curves involving a strong acid with a strong base and a weak
More informationUnit 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 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 informationQuestion Bank Electrolysis
Question Bank Electrolysis 1. (a) What do you understand by the terms (i) electrolytes (ii) non-electrolytes? (b) Arrange electrolytes and non-electrolytes from the following substances (i) sugar solution
More informationChemical Changes. Measuring a Chemical Reaction. Name(s)
Chemical Changes Name(s) In the particle model of matter, individual atoms can be bound tightly to other atoms to form molecules. For example, water molecules are made up of two hydrogen atoms bound to
More informationMolarity of Ions in Solution
APPENDIX A Molarity of Ions in Solution ften it is necessary to calculate not only the concentration (in molarity) of a compound in aqueous solution but also the concentration of each ion in aqueous solution.
More informationGetting the most from this book...4 About this book...5
Contents Getting the most from this book...4 About this book....5 Content Guidance Topic 1 Atomic structure and the periodic table...8 Topic 2 Bonding and structure...14 Topic 2A Bonding....14 Topic 2B
More informationExperiment 2 Kinetics II Concentration-Time Relationships and Activation Energy
2-1 Experiment 2 Kinetics II Concentration-Time Relationships and Activation Energy Introduction: The kinetics of a decomposition reaction involving hydroxide ion and crystal violet, an organic dye used
More informationSeparation by Solvent Extraction
Experiment 3 Separation by Solvent Extraction Objectives To separate a mixture consisting of a carboxylic acid and a neutral compound by using solvent extraction techniques. Introduction Frequently, organic
More informationExperiment 1: Colligative Properties
Experiment 1: Colligative Properties Determination of the Molar Mass of a Compound by Freezing Point Depression. Objective: The objective of this experiment is to determine the molar mass of an unknown
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 informationChemical 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
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 information= 16.00 amu. = 39.10 amu
Using Chemical Formulas Objective 1: Calculate the formula mass or molar mass of any given compound. The Formula Mass of any molecule, formula unit, or ion is the sum of the average atomic masses of all
More informationCP 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 informationANSWER KEY. Energy Levels, Electrons and IONIC Bonding It s all about the Give and Take!
ANSWER KEY Energy Levels, Electrons and IONIC Bonding It s all about the Give and Take! From American Chemical Society Middle School Chemistry Unit: Chapter 4 Content Statements: Distinguish the difference
More information15. Acid-Base Titration. Discover the concentration of an unknown acid solution using acid-base titration.
S HIFT INTO NEUTRAL 15. Acid-Base Titration Shift into Neutral Student Instruction Sheet Challenge Discover the concentration of an unknown acid solution using acid-base titration. Equipment and Materials
More informationChemistry B11 Chapter 6 Solutions and Colloids
Chemistry B11 Chapter 6 Solutions and Colloids Solutions: solutions have some properties: 1. The distribution of particles in a solution is uniform. Every part of the solution has exactly the same composition
More informationUnit 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 information4.5 Physical Properties: Solubility
4.5 Physical Properties: Solubility When a solid, liquid or gaseous solute is placed in a solvent and it seems to disappear, mix or become part of the solvent, we say that it dissolved. The solute is said
More informationLab #10 How much Acetic Acid (%) is in Vinegar?
Lab #10 How much Acetic Acid (%) is in Vinegar? SAMPLE CALCULATIONS NEED TO BE DONE BEFORE LAB MEETS!!!! Purpose: You will determine the amount of acetic acid in white vinegar (sold in grocery stores)
More informationName Class Date. What is ionic bonding? What happens to atoms that gain or lose electrons? What kinds of solids are formed from ionic bonds?
CHAPTER 1 2 Ionic Bonds SECTION Chemical Bonding BEFORE YOU READ After you read this section, you should be able to answer these questions: What is ionic bonding? What happens to atoms that gain or lose
More information5s Solubility & Conductivity
5s Solubility & Conductivity OBJECTIVES To explore the relationship between the structures of common household substances and the kinds of solvents in which they dissolve. To demonstrate the ionic nature
More informationPreparation of an Alum
Preparation of an Alum Pages 75 84 Pre-lab = pages 81 to 82, all questions No lab questions, a lab report is required by the start of the next lab What is an alum? They are white crystalline double sulfates
More informationSYNTHESIS AND ANALYSIS OF A COORDINATION COMPOUND OF COPPER
Chemistry 111 Lab: Synthesis of a Copper Complex Page H-1 SYNTHESIS AND ANALYSIS OF A COORDINATION COMPOUND OF COPPER In this experiment you will synthesize a compound by adding NH 3 to a concentrated
More informationReturn 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 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 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 informationUnit 7A - The Mole. We Need to Count atoms. The Mole and Molar Mass
Unit 7A - The Mole The Mole and Molar Mass We Need to Count atoms Airbags are inflated by a chemical reaction: electrical 2 NaN 3 (s) 3 N 2 (g) + 2 Na(s) decomposition Each airbag needs the right amount
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 informationEXPERIMENT # 3 ELECTROLYTES AND NON-ELECTROLYTES
EXPERIMENT # 3 ELECTROLYTES AND NON-ELECTROLYTES Purpose: 1. To investigate the phenomenon of solution conductance. 2. To distinguish between compounds that form conducting solutions and compounds that
More information