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

Save this PDF as:
 WORD  PNG  TXT  JPG

Size: px
Start display at page:

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

Transcription

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. If the two objects are in contact they will, given sufficient time, both reach the same temperature; we call this thermal equilibrium. Heat flow is ordinarily measured in a device called a calorimeter. A calorimeter is simply a container with insulating walls, made so that essentially no heat is exchanged between the contents of the calorimeter and the surroundings. Within the calorimeter chemical reactions may occur or heat may pass from one part of the contents to another, but no heat flows into or out of the calorimeter from or to the surrounding. A. Specific Heat. When heat flows into a substance the temperature of that substance will increase. The quantity of heat, q, required to cause a temperature change, T, of any substance is proportional to the mass, m, of the substance and the temperature change, as shown in equation (1). The proportionality constant is called the specific heat of that substance. q = (mass) x (specific heat) x T = m c T (1) The specific heat can be considered to be the amount of heat required to raise the temperature of one gram of the substance by one degree Celsius (if you make m and T in equation 1 both equal to one, then q will equal specific heat, c). Amounts of heat are measured in either joules or calories. TO raise the temperature of one gram of water by one degree Celsius 4.18 joules of heat must be added to the water. The specific heat of water is therefore 4.18 J/g C. Since 4.18 joules equals one calorie, we can say that the specific heat of water is 1.00 calories/g C. Ordinarily heat flow into or out of a substance is determined by the effect which that flow has on a known amount of water. Because water plays such an important role in these measurements the calorie, which was the unit of heat most commonly used until recently, was actually defined to be equal to the specific heat of water. The specific heat of a metal can readily be measured in a calorimeter. A weighed amount of metal is heated to some known temperature and is then quickly poured into a calorimeter that contains a measured amount of water at a known temperature. Heat flows from the metal to the water, and the two equilibrate at some temperature between the initial temperatures of the metal and the water. Assuming that no heat is lost from the calorimeter to the surroundings, and that a negligible amount of heat is absorbed by the calorimeter walls, the amount of heat that flows from the metal as it cools is equal to the amount of heat absorbed by the water. In thermodynamic terms, the heat flow for the metal is equal in magnitude but opposite in direction, and hence in sign, to that for the water. For the heat flow, q, q metal = -q water (2) If we now express heat flow in terms of equation 1 for both the water and the metal M, we get C M m M T M = C H2O m H2O T H2O (3) In this experiment we measure the masses of water and metal and their initial and final temperatures. (Note that T M <0 and T H2O.), since T = T final T initial.) Given the specific heat of water we can find the positive specific heat of the metal by equation 3. We will use this procedure to obtain the specific heat of an unknown metal.

2 The specific heat of a metal is related in a simply way to its atomic mass. Dulong and Petit discovered many years ago that about 25 joules were required to raise the temperature of one mole of many metals by one degree Celsius. This relation, shown in equation 4, is known as the Law of Dulong and Petit: AM = 25 (4) C metal (J/g C) Where AM is the atomic mass of the metal. Once the specific heat of the metal is known, the approximate atomic mass can be calculated by equation 4. The Law of Dulong and Petit was one of the few rules available to early chemists in their studies of atomic masses. (Note: 25 is an approximate, not exact #.) B. Heat of Solution. When a chemical reaction occurs in water solution, the situation is similar to that which is present when a hot metal sample is put into water. With such a reaction there is an exchange of heat between the reaction mixture and the solvent, water. As in the specific heat experiment, the heat flow for the reaction mixture is equal in magnitude but opposite in sign to that for the water. The heat flow associated with the reaction mixture is also equal to the enthalpy change, H, for the reaction, so we obtain the equation q reaction = H reaction = -q H2O (5) By measuring the mass of the water used as a solvent, and by observing the temperature change that the water undergoes, we can find q H2O by equation 1 and H by equation 5. If the temperature of the water goes up, heat has been given off by the reaction mixture, so the reaction is exothermic; q H2O, is positive and H is negative. If the temperature of the water goes down, the reaction mixture has absorbed heat from the water and the reaction is endothermic. In this case, q H2O is negative and H is positive. Both exo- and endothermic reactions are observed. One of the simplest reactions that can be studied in solution occurs when a solid is dissolved in water. As an example of such a reaction note the solution of NaOH in water. NaOH (s) Na + (aq) + OH - (aq); H = H solution (6) When this reaction occurs, the temperature of the solution becomes much higher than that of the NaOH and water that were sued. If we dissolve a known amount of NaOH in a measured amount of water in a calorimeter, and measure the temperature change that occurs, we can use equation 1 to find q H2O for the reaction and use equation 5 to obtain H. Noting that H is directly proportional to the amount of NaOH used, we can easily calculate H solution for either a gram or a mole of NaOH. In the second part of this experiment you will measure H solution for an unknown ionic solid. EXPERIMENTAL PROCEDURE Wear your safety glasses while performing this experiment: Part A Specific Heat of a Metal. From your instructor obtain a calorimeter, a sensitive thermometer, a sample of metal in a large stoppered test tube. The calorimeter consists of two nested expanded polystyrene coffee cups fitted with a Styrofoam cover. There are two holes in the cover for a thermometer and a glass stirring rode with a loop bent on one end. Assemble the experimental setup as shown in figure 1. Fill a 400-mL beaker two-thirds full of water and begin heating it to boiling. Fill a 100-mL beaker two-thirds full of water and begin heating it to boiling a well. While the water is heating, weight your sample of unknown metal in the large stoppered test tube to the nearest 0.1g on a top loading balance. Pour the metal into a dry container and weigh the empty test tube and stopper. Replace the metal in the test tube and put the LOOSELY stoppered tube into the hot water in the400-ml beaker. The water level in the 400-mL beaker should be high enough so that the top of the metal is below the water surface. Continue heating the metal in the water for at least 5 minutes after the water begins to boil to ensure that the metal attains the temperature of the boiling water. Add water as necessary from your 100-mL beaker to the 400-mL beaker to maintain the water level.

3 While the water is boiling, mass the calorimeter t0 the nearest 0.01 g. Place about 40 ml of water in the calorimeter and mass again. Insert the stirrer and thermometer into the cover and put it on the calorimeter. The thermometer bulb should be completely under the water. BE CAREFUL SO THAT YOU DO NO PUNCTURE THE CUP. Measure the temperature of the water in the calorimeter to the nearest 0.1 C. Take the test tube out of the beaker of boiling water, remove the stopper, and pour the metal into the water in the calorimeter. Be careful so that no water adhering to the outside of the test tube runs into the calorimeter when you are pouring the metal. Replace the calorimeter cover and agitate the water as best you can with the glass stirrer. Record to the nearest 0.1 C the maximum temperature reached by the water. Be sure to dry your metal before reusing it; this can be done by heating the metal briefly in the test tube in boiling water and then pouring the metal onto a paper towel to drain. You can dry the hot test tube with a towel. When this portion of the experiment is completed, dry your metal once again in the boiling water bath. Return the metal to your instructor by pouring the metal onto a large watch glass provided by your instructor. Carefully place the test tube and stopper on top of the watch glass with the metal. (Note: Even though the Law of Dulong and Petit really only allows us to know the molar mass to 2 significant figures, we will round all calculated molar masses to the ones place even if that requires keeping 3 significant figures.) Part B Heat of Solution. Obtain a calorimeter similar to the one used in part A or simply use the same calorimeter. Mass the calorimeter on a top loading balance to the nearest 0.01 g. Place about 50 ml of distilled water in the calorimeter and mass to the nearest 0.01g. Measure the temperature of the water to 0.1 C. The temperature should be within a degree or two of room temperature. Tare the mass of a small weigh boat, then add about 6 to 7 grams of the unknown ionic solid assigned to you. Record the mass to the nearest 0.01g. Be sure to record the number of your solid in your data table. Add the solid from the weigh boat to the water in the calorimeter. Stirring continuously and occasionally swirling the calorimeter, determine to 0.1 C the maximum or minimum temperature reacted as the solid dissolved. (Caution: You need to stir really well and swirl occasionally to get all the solid to dissolve.) Check to make sure that all the solid dissolved. A temperature change of at least five degrees should be obtained in this experiment. If necessary, repeat the experiment, increasing the amount of solid used. Clean out cup, and dry completely before returning to your instructor.

4 Experiment: Calorimetry Name: Block: Pre-lab Heat Effects and Calorimetry (To be handed in before starting the experiment.) SHOW SET-UPS FOR CREDIT. 1. A metal sample with a mass of 63.2 g. and at a temperature of C was placed in 41.0 g. of water in a calorimeter at 24.5 C. At equilibrium the temperature of the water and metal was 35.0 C. A. What was T for the water? ( T = T final T initial ) B. What was T for the metal? C. Taking the specific heat of water to be 4.18J/g C, calculate the specific heat of the metal, using equation 3. D. What is the approximate atomic mass of the metal? (Use equation 4.) 2. When 5.0 g of KNO 3 were dissolved in 49.0 g. water in a calorimeter at 24.0 C, the temperature of the solution fell to 15.6 C. A. Is this solution reaction exothermic? Why? B. What was T for the water? ( T = T final T initial ) C. Calculate q H2O, using equation 1. D. Find q for the reaction as it occurred in the calorimeter (equation 5). E. Find H solution in joules/g H = F. Find H solution in joules/mole H = G. Write the chemical equation that represents the heat of solution for KNO 3. H. Using enthalpies of formation, H f, given in the back of your text book (A19-A22) to calculate H solution for the reaction in part G. (Reminder: H rxn = Σ H f products - Σ H f reactants) I. Calculate your percent error using your answers to part F and H.

5 Experiment: Calorimetry Name: Block: Post-lab Heat Effects and Calorimetry Due: Day after lab. Part A Specific Heat of a Metal. 1. For the following errors describe how they would affect your calculated specific heat increase, decrease, remain the same). a. The metal did not reach thermal equilibrium with the boiling water. b. When pouring the metal into the distilled water, some hot water from the wet test tube fell into the distilled water as well.. c. Heat from the warming water was lost to the surroundings. d. The mass of the empty test tube was taken when the test tube was slightly wet. e. The initial temperature of the water was recorded higher than it actually was by reading the thermometer from above. Part B Heat of Solution. 1. We found the heat of solution of an ionic solid for part B of this lab. Describe heat of solution briefly in your own words. 2. If we were to graph the entire class s results for this lab, would we likely have a. Mostly low results b. Mostly high results c. Approximately equal number of low and high results 3. Given your answer to #2, did we have random or systematic error? 4. For the following errors describe how they would affect your calculated heat of solution. a. Not all of the ionic solid was dissolved. b. The ionic solid dissolved slowly enough that much of the heat dissipated to the surroundings. c. The student recording the initial temperature of the distilled water did not wait for the thermometer to come to thermal equilibrium with the distilled water prior to recording the initial temperature. (The temperature of the room was warmer than was the distilled water.) d. The ionic solid had absorbed come water from the air prior to being dissolved in the distilled water. e. The balance read zero prior to placing the weigh boat on it. The student did not tare the mass of the weigh boat prior to adding the ionic solid. The balance read 6.00 grams with the weigh boat and solid on it. The student recorded the mass of the ionic solid as 6.00 grams.

Experiment 6 Coffee-cup Calorimetry

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

More information

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

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

More information

Thermochemistry I: Endothermic & Exothermic Reactions

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

More information

HEAT OF FORMATION OF AMMONIUM NITRATE

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

More information

Thermochemistry: Calorimetry and Hess s Law

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

More information

DETERMINING THE ENTHALPY OF FORMATION OF CaCO 3

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

More information

Hands-On Labs SM-1 Lab Manual

Hands-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 information

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

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

More information

To measure the solubility of a salt in water over a range of temperatures and to construct a graph representing the salt solubility.

To 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 information

PREPARATION FOR CHEMISTRY LAB: COMBUSTION

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

More information

EXPERIMENT 7 Reaction Stoichiometry and Percent Yield

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

More information

Freezing Point Depression: Why Don t Oceans Freeze? Teacher Advanced Version

Freezing 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 information

SOLUBILITY OF A SALT IN WATER AT VARIOUS TEMPERATURES LAB

SOLUBILITY 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 information

Chapter 18 Temperature, Heat, and the First Law of Thermodynamics. Problems: 8, 11, 13, 17, 21, 27, 29, 37, 39, 41, 47, 51, 57

Chapter 18 Temperature, Heat, and the First Law of Thermodynamics. Problems: 8, 11, 13, 17, 21, 27, 29, 37, 39, 41, 47, 51, 57 Chapter 18 Temperature, Heat, and the First Law of Thermodynamics Problems: 8, 11, 13, 17, 21, 27, 29, 37, 39, 41, 47, 51, 57 Thermodynamics study and application of thermal energy temperature quantity

More information

Mixtures and Pure Substances

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

More information

Thermochemical equations allow stoichiometric calculations.

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

More information

Thermochemistry. r2 d:\files\courses\1110-20\99heat&thermorans.doc. Ron Robertson

Thermochemistry. 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 information

Experiment 1: Colligative Properties

Experiment 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 information

1. The Determination of Boiling Point

1. The Determination of Boiling Point 1. The Determination of Boiling Point Objective In this experiment, you will first check your thermometer for errors by determining the temperature of two stable equilibrium systems. You will then use

More information

Isolation of Caffeine from Tea

Isolation of Caffeine from Tea Isolation of Caffeine from Tea Introduction A number of interesting, biologically active compounds have been isolated from plants. Isolating some of these natural products, as they are called, can require

More information

Determination of a Chemical Formula

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

More information

The Empirical Formula of a Compound

The Empirical Formula of a Compound The Empirical Formula of a Compound Lab #5 Introduction A look at the mass relationships in chemistry reveals little order or sense. The ratio of the masses of the elements in a compound, while constant,

More information

Bomb Calorimetry. Example 4. Energy and Enthalpy

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

More information

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 ) 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 information

Exp 13 Volumetric Analysis: Acid-Base titration

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

More information

EXPERIMENT 15: Ideal Gas Law: Molecular Weight of a Vapor

EXPERIMENT 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 information

SUPPLEMENTARY MATERIAL

SUPPLEMENTARY 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 information

experiment5 Understanding and applying the concept of limiting reagents. Learning how to perform a vacuum filtration.

experiment5 Understanding and applying the concept of limiting reagents. Learning how to perform a vacuum filtration. 81 experiment5 LECTURE AND LAB SKILLS EMPHASIZED Synthesizing an organic substance. Understanding and applying the concept of limiting reagents. Determining percent yield. Learning how to perform a vacuum

More information

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

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

More information

Determination of Molar Mass by Boiling Point Elevation of Urea Solution

Determination of Molar Mass by Boiling Point Elevation of Urea Solution Determination of Molar Mass by Boiling Point Elevation of Urea Solution CHRISTIAN E. MADU, PhD AND BASSAM ATTILI, PhD COLLIN COLLEGE CHEMISTRY DEPARTMENT Purpose of the Experiment Determine the boiling

More information

Properties of Acids and Bases

Properties of Acids and Bases Lab 22 Properties of Acids and Bases TN Standard 4.2: The student will investigate the characteristics of acids and bases. Have you ever brushed your teeth and then drank a glass of orange juice? What

More information

Recovery of Elemental Copper from Copper (II) Nitrate

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

More information

ph: Measurement and Uses

ph: 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 information

Pre-Lab Notebook Content: Your notebook should include the title, date, purpose, procedure; data tables.

Pre-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 information

Mixing Warm and Cold Water

Mixing Warm and Cold Water Mixing Warm and Cold Water A Continuing Investigation of Thermal Pollution By Kevin White 1 Context: This lesson is intended for students conducting an ongoing study of thermal pollution. Perhaps, students

More information

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

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

More information

Determination of Molar Mass by Freezing-Point Depression

Determination of Molar Mass by Freezing-Point Depression DETERMINATION OF MOLAR MASS BY FREEZING-POINT DEPRESSION 141 Determination of Molar Mass by Freezing-Point Depression OBJECTIVES: Gain familiarity with colligative properties of nonelectrolyte solutions

More information

SEPARATION OF A MIXTURE OF SUBSTANCES LAB

SEPARATION OF A MIXTURE OF SUBSTANCES LAB SEPARATION OF A MIXTURE OF SUBSTANCES LAB Purpose: Every chemical has a set of defined physical properties, and when combined they present a unique fingerprint for that chemical. When chemicals are present

More information

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

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

More information

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

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

More information

Energy and Chemical Reactions. Characterizing Energy:

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

More information

Experiment 7: Titration of an Antacid

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

More information

Physical Properties of a Pure Substance, Water

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

More information

Solubility Curve of Sugar in Water

Solubility Curve of Sugar in Water Solubility Curve of Sugar in Water INTRODUCTION Solutions are homogeneous mixtures of solvents (the larger volume of the mixture) and solutes (the smaller volume of the mixture). For example, a hot chocolate

More information

AN EXPERIMENT IN ALCHEMY: COPPER TO SILVER TO GOLD 2005, 2000, 1996 by David A. Katz. All rights reserved

AN EXPERIMENT IN ALCHEMY: COPPER TO SILVER TO GOLD 2005, 2000, 1996 by David A. Katz. All rights reserved AN EXPERIMENT IN ALCHEMY: COPPER TO SILVER TO GOLD 2005, 2000, 1996 by David A. Katz. All rights reserved INTRODUCTION One of the goals of the ancient alchemists was to convert base metals into gold. Although

More information

Distillation Experiment

Distillation Experiment Distillation Experiment CHM226 Background The distillation process is a very important technique used to separate compounds based on their boiling points. A substance will boil only when the vapor pressure

More information

Electrical Conductivity of Aqueous Solutions

Electrical Conductivity of Aqueous Solutions Electrical Conductivity of Aqueous Solutions PRE-LAB ASSIGNMENT: Reading: Chapter 4.-4.3 in Brown, LeMay, Bursten & Murphy.. Using Table in this handout, determine which solution has a higher conductivity,.

More information

Investigation M3: Separating Mixtures into Component Parts

Investigation M3: Separating Mixtures into Component Parts Investigation M3: Separating Mixtures into Component Parts Goals: Use various methods to separate mixtures, make inferences from temperature/time graphs, and identify substances. 81 Activity M3.3: What

More information

EXPERIMENT 12 A SOLUBILITY PRODUCT CONSTANT

EXPERIMENT 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 information

Oxidation States of Copper Two forms of copper oxide are found in nature, copper(i) oxide and copper(ii) oxide.

Oxidation States of Copper Two forms of copper oxide are found in nature, copper(i) oxide and copper(ii) oxide. The Empirical Formula of a Copper Oxide Reading assignment: Chang, Chemistry 10 th edition, pp. 55-58. Goals The reaction of hydrogen gas with a copper oxide compound will be studied quantitatively. By

More information

Preparation of an Alum

Preparation 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 information

Test 5 Review questions. 1. As ice cools from 273 K to 263 K, the average kinetic energy of its molecules will

Test 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

Experiment 12- Classification of Matter Experiment

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

More information

Experiment 8 Synthesis of Aspirin

Experiment 8 Synthesis of Aspirin Experiment 8 Synthesis of Aspirin Aspirin is an effective analgesic (pain reliever), antipyretic (fever reducer) and anti-inflammatory agent and is one of the most widely used non-prescription drugs. The

More information

Solubility Product Constants

Solubility Product Constants Solubility Product Constants PURPOSE To measure the solubility product constant (K sp ) of copper (II) iodate, Cu(IO 3 ) 2. GOALS 1 To measure the molar solubility of a sparingly soluble salt in water.

More information

PHYSICAL SEPARATION TECHNIQUES. Introduction

PHYSICAL SEPARATION TECHNIQUES. Introduction PHYSICAL SEPARATION TECHNIQUES Lab #2 Introduction When two or more substances, that do not react chemically, are blended together, the result is a mixture in which each component retains its individual

More information

Determining Equivalent Weight by Copper Electrolysis

Determining Equivalent Weight by Copper Electrolysis Purpose The purpose of this experiment is to determine the equivalent mass of copper based on change in the mass of a copper electrode and the volume of hydrogen gas generated during an electrolysis reaction.

More information

Designing An Experiment Using Baking Soda and Vinegar

Designing An Experiment Using Baking Soda and Vinegar Designing An Experiment Using Baking Soda and Vinegar Introduction: Kinetics is the study of chemical reaction rates. It is the study of how fast different chemicals react with one another to form new

More information

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

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

More information

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

General Chemistry I (FC, 09-10) Lab #3: The Empirical Formula of a Compound. Introduction General Chemistry I (FC, 09-10) Introduction A look at the mass relationships in chemistry reveals little order or sense. The ratio of the masses of the elements in a compound, while constant, does not

More information

CHEMICAL REACTIONS OF COPPER AND PERCENT YIELD KEY

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

More information

Experiment 8 - Double Displacement Reactions

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

More information

UNIT 1 THERMOCHEMISTRY

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

More information

Acid Base Titrations

Acid Base Titrations Acid Base Titrations Introduction A common question chemists have to answer is how much of something is present in a sample or a product. If the product contains an acid or base, this question is usually

More information

Experiment 12E LIQUID-VAPOR EQUILIBRIUM OF WATER 1

Experiment 12E LIQUID-VAPOR EQUILIBRIUM OF WATER 1 Experiment 12E LIQUID-VAPOR EQUILIBRIUM OF WATER 1 FV 6/26/13 MATERIALS: PURPOSE: 1000 ml tall-form beaker, 10 ml graduated cylinder, -10 to 110 o C thermometer, thermometer clamp, plastic pipet, long

More information

Calcium Analysis by EDTA Titration

Calcium Analysis by EDTA Titration Calcium Analysis by EDTA Titration ne of the factors that establish the quality of a water supply is its degree of hardness. The hardness of water is defined in terms of its content of calcium and magnesium

More information

CHEMICAL DETERMINATION OF EVERYDAY HOUSEHOLD CHEMICALS

CHEMICAL 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 information

The Determination of an Equilibrium Constant

The Determination of an Equilibrium Constant The Determination of an Equilibrium Constant Computer 10 Chemical reactions occur to reach a state of equilibrium. The equilibrium state can be characterized by quantitatively defining its equilibrium

More information

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

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

More information

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

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

More information

Lesson 4. Temperature change

Lesson 4. Temperature change 54 Lesson 4 Temperature change T E A C H E R G U I D E Lesson summary Students meet scientist Jason Williams, an industrial chemist who designs the materials and processes for making solar cells. He explains

More information

CHEM 2423 Recrystallization of Benzoic Acid EXPERIMENT 4 - Purification - Recrystallization of Benzoic acid

CHEM 2423 Recrystallization of Benzoic Acid EXPERIMENT 4 - Purification - Recrystallization of Benzoic acid EXPERIMENT 4 - Purification - Recrystallization of Benzoic acid Purpose: a) To purify samples of organic compounds that are solids at room temperature b) To dissociate the impure sample in the minimum

More information

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

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

More information

Specific Heat (slope and steepness)

Specific Heat (slope and steepness) 1 Specific Heat (slope and steepness) 10 pages. According to the Physical Science text book, the Specific Heat of a material is DEFINED as the following: Specific heat is the amount of heat energy required

More information

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

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

More information

Experiment 5 Preparation of Cyclohexene

Experiment 5 Preparation of Cyclohexene Experiment 5 Preparation of yclohexene In this experiment we will prepare cyclohexene from cyclohexanol using an acid catalyzed dehydration reaction. We will use the cyclohexanol that we purified in our

More information

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

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

More information

Net ionic equation: 2I (aq) + 2H (aq) + H O (aq) I (s) + 2H O(l)

Net ionic equation: 2I (aq) + 2H (aq) + H O (aq) I (s) + 2H O(l) Experiment 5 Goals To determine the differential rate law for the reaction between iodide and hydrogen peroxide in an acidic environment. To determine the activation energy and pre-exponential factor for

More information

ENTHALPY CHANGES FOR A CHEMICAL REACTION scaling a rxn up or down (proportionality) quantity 1 from rxn heat 1 from Δ r H. = 32.

ENTHALPY 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 information

The most common active ingredient used in deodorants is aluminium chlorohydrate. But not all deodorants contain aluminium chlorohydrate:

The most common active ingredient used in deodorants is aluminium chlorohydrate. But not all deodorants contain aluminium chlorohydrate: Engineeringfragrance make a deodorant practical activity 2 student instructions page 1 of 5 chemical compounds The most common active ingredient used in deodorants is aluminium chlorohydrate. But not all

More information

EXPERIMENT 12: Empirical Formula of a Compound

EXPERIMENT 12: Empirical Formula of a Compound EXPERIMENT 12: Empirical Formula of a Compound INTRODUCTION Chemical formulas indicate the composition of compounds. A formula that gives only the simplest ratio of the relative number of atoms in a compound

More information

Experiment 3 Limiting Reactants

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

More information

The Molar Mass of a Gas

The Molar Mass of a Gas The Molar Mass of a Gas Goals The purpose of this experiment is to determine the number of grams per mole of a gas by measuring the pressure, volume, temperature, and mass of a sample. Terms to Know Molar

More information

5. Which temperature is equal to +20 K? 1) 253ºC 2) 293ºC 3) 253 C 4) 293 C

5. Which temperature is equal to +20 K? 1) 253ºC 2) 293ºC 3) 253 C 4) 293 C 1. The average kinetic energy of water molecules increases when 1) H 2 O(s) changes to H 2 O( ) at 0ºC 3) H 2 O( ) at 10ºC changes to H 2 O( ) at 20ºC 2) H 2 O( ) changes to H 2 O(s) at 0ºC 4) H 2 O( )

More information

The Atomic Mass of an Unknown Metal

The Atomic Mass of an Unknown Metal The Atomic Mass of an Unknown Metal Background Historically, a relative atomic mass scale for the elements was gradually assembled from many experiments leading up to Mendeleev's eventual arrangement of

More information

The Structure of Water Introductory Lesson

The Structure of Water Introductory Lesson Dana V. Middlemiss Fall 2002 The Structure of Water Introductory Lesson Abstract: This is an introduction to the chemical nature of water and its interactions. In particular, this lesson will explore evaporation,

More information

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

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

More information

CHEMISTRY STANDARDS BASED RUBRIC ATOMIC STRUCTURE AND BONDING

CHEMISTRY 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 information

Determination of the enthalpy of combustion using a bomb calorimeter TEC

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

More information

EXPERIMENT 9 (Organic Chemistry II) Pahlavan - Cherif Synthesis of Aspirin - Esterification

EXPERIMENT 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 information

States of Matter CHAPTER 10 REVIEW SECTION 1. Name Date Class. Answer the following questions in the space provided.

States 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 information

Phenolphthalein-NaOH Kinetics

Phenolphthalein-NaOH Kinetics Phenolphthalein-NaOH Kinetics Phenolphthalein is one of the most common acid-base indicators used to determine the end point in acid-base titrations. It is also the active ingredient in some laxatives.

More information

Electrochemical Half Cells and Reactions

Electrochemical Half Cells and Reactions Suggested reading: Chang text pages 81 89 Cautions Heavy metals, such as lead, and solutions of heavy metals may be toxic and an irritant. Purpose To determine the cell potential (E cell ) for various

More information

Experiment 13: Determination of Molecular Weight by Freezing Point Depression

Experiment 13: Determination of Molecular Weight by Freezing Point Depression 1 Experiment 13: Determination of Molecular Weight by Freezing Point Depression Objective: In this experiment, you will determine the molecular weight of a compound by measuring the freezing point of a

More information

Dissolving of sodium hydroxide generates heat. Take care in handling the dilution container.

Dissolving of sodium hydroxide generates heat. Take care in handling the dilution container. TITRATION: STANDARDIZATION OF A BASE AND ANALYSIS OF STOMACH ANTACID TABLETS 2009, 1996, 1973 by David A. Katz. All rights reserved. Reproduction permitted for education use provided original copyright

More information

2. Room temperature: C. Kelvin. 2. Room temperature:

2. Room temperature: C. Kelvin. 2. Room temperature: Temperature I. Temperature is the quantity that tells how hot or cold something is compared with a standard A. Temperature is directly proportional to the average kinetic energy of molecular translational

More information

Thermodynamics. Thermodynamics 1

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

More information

Chapter 10 Temperature and Heat

Chapter 10 Temperature and Heat Chapter 10 Temperature and Heat What are temperature and heat? Are they the same? What causes heat? What Is Temperature? How do we measure temperature? What are we actually measuring? Temperature and Its

More information

STANDARDIZATION OF A SODIUM HYDROXIDE SOLUTION EXPERIMENT 14

STANDARDIZATION OF A SODIUM HYDROXIDE SOLUTION EXPERIMENT 14 STANDARDIZATION OF A SODIUM HYDROXIDE SOLUTION EXPERIMENT 14 OBJECTIVE The objective of this experiment will be the standardization of sodium hydroxide using potassium hydrogen phthalate by the titration

More information

Evaluation copy. Titration of a Diprotic Acid: Identifying an Unknown. Computer

Evaluation copy. Titration of a Diprotic Acid: Identifying an Unknown. Computer Titration of a Diprotic Acid: Identifying an Unknown Computer 25 A diprotic acid is an acid that yields two H + ions per acid molecule. Examples of diprotic acids are sulfuric acid, H 2 SO 4, and carbonic

More information