Determination of the Percentage Oxygen in Air

Save this PDF as:

Size: px
Start display at page:

Download "Determination of the Percentage Oxygen in Air"

Transcription

1 CHEM 121L General Chemistry Laboratory Revision 1.1 Determination of the Percentage Oxygen in Air In this laboratory exercise we will determine the percentage by volume of Oxygen in Air. We will do this by allowing the Oxygen in the Air to react with Iron in the form of Steel Wool. This will convert the gaseous Oxygen into solid Iron Oxide. This will cause the volume of the Air to decrease as it becomes devoid of Oxygen. Once the reaction is complete, the decrease in the Air s volume will be equal to the volume the gaseous Oxygen occupied in the Air. One of the earliest observations concerning combustion was that it stops when the supply of Air is removed from the combustible material. Various theories were put forth to explain this observation. The first of these theories to take hold was the Theory of Phlogiston. This theory, put forth in 1667 by Johann Joachim Becher, postulated; that bodies were composed of three earths - terra lapidea (vitreous), terra mercurialis (mercurial), terra pinguis (fatty). [Becher] considered combustible substances to be rich in terra pinguis, which was lost during burning,. Even metals that were calcinable contained some of the fatty earth. [These ideas were] later developed into an elaborate chemical system in which the term "phlogiston" replaced terra pinguis. The Development of Modern Chemistry Aaron J. Ihde

2 P a g e 2 According to this theory, during combustion, a hypothetical substance called Phlogiston is released. Air was believed to absorb the Phlogiston until a point of saturation. It is at this saturation point that combustion ceases, unless fresh Air is introduced. Material Dephlogisticated Material + Phlogisticated Air This theory was capable of explaining not only combustion and calcination, but was also capable of explaining the smelting of metal ores and respiration. Although inconvenient facts kept pointing to inconsistencies in the Theory of Phlogiston, it was not until the discovery of the gas Oxygen in the late 1700's that it was finally abandoned. Gaseous Oxygen was first produced by Carl Wilhelm Steele in 1774 when, as a result of the strong heating of the Red Calx of Mercury (Mercuric Oxide), the Calx decomposed into elemental Mercury and a gaseous substance now known as Oxygen. Antoine Lavoisier and Joseph Priestley were then able to show that Oxygen is a component of Air and is required for combustion and respiration. With these discoveries it was realized that Air supports combustion because of the presence of Oxygen. When Air is depleted of Oxygen, it no longer supports combustion. Material + Oxygen Oxide of the Material Although it seems as though the Theory of Phlogiston has merely been inverted, Oxygen is an isolatable substance, whereas Phlogiston is not. Additionally, all those inconvenient facts unexplainable by the Theory of Phlogiston suddenly become explainable by the presence and reactivity of Oxygen. Thus, as Ihde points out; "The phlogiston concept gradually disappeared as its elder adherents were removed from the scene by death." Lavoisier was able to show that Air that combined with elemental Mercury lost about 1/6 of its volume. In turn, he was able to regenerate this volume of gas by decomposing the Red Calx that formed. Thus, he reasoned, Air is approximately 1/6 Oxygen. We will do something similar in our determination of the Oxygen content of Air. We will combine Air with elemental Iron. In the presence of Water and an acid catalyst, the Oxygen in Air reacts with Iron to form a complex Hydrate: 2 Fe(s) + 3 O 2 (g) + x H 2 O Fe 2 O 3 xh 2 O(s) (Eq. 1) We must be careful not to use too much acid, however, because if the system is too acidic the Iron will react directly with the acid to form Hydrogen gas: Fe(s) + 2 H + (aq) Fe 2+ (aq) + H 2 (a) (Eq. 2) Thus, we will soak Steel Wool in a dilute aqueous solution of Acetic Acid and allow it to react with the Oxygen in Air. As it does this, the volume of the Air will contract. When complete, the

3 P a g e 3 volume lost by the Air will be equal to the volume Oxygen initially present. We will measure this volume lost by the Air by carrying out this reaction in an inverted test tube placed in a bath of Water. As the Oxygen is depleted from the Air and its volume contracts, Water will rush into the test tube to replace it. By measuring the volume of this Water, we will be measuring the volume of Oxygen in the Air. This method of measuring the volume of Oxygen in Air has one draw-back. The Air above the Water is Moist due to some Water Vapor that will be present in the gas. We can, however, correct for this by subtracting out the volume of the Air occupied by the Water Vapor. Thus, by applying an appropriate correction factor, we can determine the Volume Percentage Oxygen in Dry Air. We can then compare this determination with the accepted literature result.

4 P a g e 4 Pre-Lab Questions 1. Dry Air is reported to be 20.94% Oxygen. What is the Percentage Error in Lavoisier s determination? 2. Write a balanced chemical reaction for Scheele s method for producing Oxygen. 3. The word Oxygen is derived from the Greek word οξυγόνο. What is the meaning of this word and why was it selected as the name for Scheele s new gas?

5 P a g e 5 Procedure 1. Obtain two 20 x 150 test tubes without lips. Mark each tube, from the open end, using a wax pencil, every 0.5 cm for a total length of 6 cm. (You will use these markings to judge the rate of reaction by observing how fast Water fills the tube.) Arrange to clamp these tubes to a ring stand in an inverted position in a 1 L beaker filled with tap Water. 2. On an Analytical Balance, weigh out two ~0.5g pieces of fine Steel Wool (size 00). Do not compress the Wool. 3. In a fume hood, obtain 50mL Acetone, 50 ml of 1.0 M Acetic Acid and 50 ml 0.1 M Acetic Acid in 100 ml beakers. 4. Using forceps, in a fume hood, rinse one of the pieces of Wool in Acetone for about 30 seconds. This will remove any oil from the surface of the Steel Wool. Shake off the excess Acetone and drain it briefly on a paper towel. Do not compress the Steel Wool. 5. Transfer the Wool to the 1 M Acetic Acid. Agitate the Wool in the Acid for about 1 minute. This will help remove any Oxide coating from the Steel Wool and prepare the Wool s surface for reaction with Oxygen. Shake off the excess acid and drain the Wool briefly on a paper towel. Do not compress the Steel Wool. 6. Transfer the Wool to the 0.1 M Acetic Acid. Agitate the Wool in the Acid for about 30 seconds. Remove the Wool and shake it vigorously in the sink to remove as much of the acidic solution as possible. A small amount of this solution will remain adhered to the Wool s surface. This will provide the aqueous acidic solution required to catalyze the reaction between the Iron and the Oxygen. Do not compress the Steel Wool.

6 P a g e 6 7. Insert the Steel Wool into the bottom third of your test tube. Do not compress the Wool as you want as much surface area exposed to the Air as possible. 8. Invert the test tube and lower it into a water tank and clamp it into place. The mouth of the beaker must be below the level of the Water throughout the experiment. 9. At 5 minute intervals, note the level of the Water in the tube. Also, at some point during the reaction measure the temperature of the Water. We will take this temperature to be the temperature of the Air in the test tube. 10. Prepare a second sample of Wool for a second trial. Start the second trial while you are waiting for the first trial to be completed. 11. On a Top-Loading Balance, weigh a 250 ml beaker. 12. When the level of the Water in the test tube is no longer rising, wait 5 minutes longer and then adjust the height of the Water in the test tube such that it equals that of the Water in the beaker. (This will ensure the pressure of the gas in the tube is equal to that of the atmosphere. Think about why this is necessary in terms of Boyle s Law.) 13. Trap the Water in the test tube by firmly holding a large rubber stopper against the mouth of the tube while the mouth of the tube is still under Water. 14. Unclamp the test tube and remove it from the Water. Have your lab partner tap dry your hand, the stopper and the test tube. Quickly transfer the trapped Water to the weighed beaker. Re-weigh the beaker. 15. Using forceps remove the Steel Wool from the test tube and transfer it to the weighed beaker with the Water. Re-weigh the beaker and its contents. 16. Now, fill the test tube to the brim with Water. Add this to the beaker and re-weigh it. 17. Complete your second trial. 18. Measure the barometric pressure of the Atmosphere. When the level of the Water in the test tube is equal to the level of the Water in the beaker, the Atmospheric pressure is equal to the pressure of the gas in the tube.

7 P a g e 7 Data Analysis 1. Calculate the volume of Oxygen in the Moist Air from the mass of the Water trapped in the test tube. (Take the density of Water to be g/ml at Room Temperature.) Mass Water Trapped = Mass Step #14 Mass Step #11 2. Calculate the volume of the Steel Wool in the test tube from its initial mass. (Take the density of Steel Wool to be 7.70 g/ml.) Mass Steel Wool = Mass Step #2 3. Calculate the volume of the solution adhering to the Steel Wool. (Take the density of the adhering solution to be g/ml.) Mass Adhering Solution = Mass Step #15 - Mass Step #13 - Mass Step #2 4. Calculate the volume of the test tube from the mass of the Water that fills the test tube. (Take the density of Water to be g/ml at Room Temperature.) Mass Water in Full Tube = Mass Step #16 - Mass Step #15 5. Calculate the volume of the Air initially in the test tube. This will equal the volume of the test tube minus the volume of the Steel Wool and the volume of the adhering solution. Volume = Data Anal. Step #4 - Data Anal. Step #2 - Data Anal. Step #3 6. Calculate the percentage of Oxygen in the Moist Air. 7. Because the Air above the Water in the test tube contains some Water Vapor, we must correct this result to obtain the percentage Oxygen in Dry Air. Recall, the pressure of the gas in the test tube is equal to the barrometric pressure; P gas = P Barr. So, we need to subtract out the Vapor Pressure of Water P H2O and correct the % Oxygen in Moist Air according to: % Oxygen in Moist Air = % Oxygen in Dry Air x (P Barr - P H2O ) / P Barr Values for the Vapor Pressure of Water can be found in the Appendix. Calculate the percentage Oxygen in Dry Air. 8. Dry Air is reported to be 20.94% Oxygen. Calculate the percentage error for your determination.

8 P a g e 8

9 P a g e 9 Post Lab Questions 1. One of the inconvenient facts the Phlogistonists had to contend with was that metals were observed to increase in mass when they calcinate. Why was this fact inconvenient and how did the Phlogistonists explain it? 2. How would our results be affected if the solution adhering to the Steel Wool is too acidic and this resulted in the production of Hydrogen gas? 3. How many moles of Oxygen are contained in 10 ml of the pure gas at 25 o C and 1 atm pressure? How many grams of Iron is required to react with this much Oxygen?

10 P a g e 10 Appendix - Vapor Pressure and Density of Water Temp [ o C] Vapor Press [mmhg] Density [g/ml]

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

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

Molar Mass of Butane

Molar Mass of Butane Cautions Butane is toxic and flammable. No OPEN Flames should be used in this experiment. Purpose The purpose of this experiment is to determine the molar mass of butane using Dalton s Law of Partial Pressures

More information

CSUS Department of Chemistry Experiment 8 Chem.1A

CSUS Department of Chemistry Experiment 8 Chem.1A EXPERIMENT #8 Name: PRE-LABORATORY ASSIGNMENT: Lab Section 1. The alkali metals are so reactive that they react directly with water in the absence of acid. For example, potassium reacts with water as follows:

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

The Empirical Formula of a Compound

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

More information

EXPERIMENT 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

EXPERIMENT 9 Evaluation of the Universal Gas Constant, R

EXPERIMENT 9 Evaluation of the Universal Gas Constant, R Outcomes EXPERIMENT 9 Evaluation of the Universal Gas Constant, R After completing this experiment, the student should be able to: 1. Determine universal gas constant using reaction of an acid with a metal.

More information

Molar Mass and the Ideal Gas Law Prelab

Molar Mass and the Ideal Gas Law Prelab Molar Mass and the Ideal Gas Law Prelab Name Total /10 SHOW ALL WORK NO WORK = NO CREDIT 1. What is the purpose of this experiment? 2. Determine the mass (in grams) of magnesium metal required to produce

More information

DETERMINING THE MOLAR MASS OF CARBON DIOXIDE

DETERMINING THE MOLAR MASS OF CARBON DIOXIDE DETERMINING THE MOLAR MASS OF CARBON DIOXIDE PURPOSE: The goal of the experiment is to determine the molar mass of carbon dioxide and compare the experimentally determined value to the theoretical value.

More information

Austin Peay State University Department of Chemistry CHEM 1111. Empirical Formula of a Compound

Austin Peay State University Department of Chemistry CHEM 1111. Empirical Formula of a Compound Cautions Magnesium ribbon is flammable. Nitric acid (HNO 3 ) is toxic, corrosive and contact with eyes or skin may cause severe burns. Ammonia gas (NH 3 ) is toxic and harmful. Hot ceramic crucibles and

More information

AP CHEMISTRY 2009 SCORING GUIDELINES (Form B)

AP CHEMISTRY 2009 SCORING GUIDELINES (Form B) AP CHEMISTRY 2009 SCORING GUIDELINES (Form B) Question 3 (10 points) 2 H 2 O 2 (aq) 2 H 2 O(l) + O 2 (g) The mass of an aqueous solution of H 2 O 2 is 6.951 g. The H 2 O 2 in the solution decomposes completely

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

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

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

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

Chemistry 212 VAPOR PRESSURE OF WATER LEARNING OBJECTIVES

Chemistry 212 VAPOR PRESSURE OF WATER LEARNING OBJECTIVES Chemistry 212 VAPOR PRESSURE OF WATER LEARNING OBJECTIVES The learning objectives of this experiment are to explore the relationship between the temperature and vapor pressure of water. determine the molar

More information

Laboratory Exercise: Smelting of Lead

Laboratory Exercise: Smelting of Lead CHEM 109 Introduction to Chemistry Revision 1.0 Laboratory Exercise: Smelting of Lead In this laboratory exercise we will carry out a pyrometallurgical conversion of Lead Oxide into elemental Lead. This

More information

Chemistry 101 Generating Hydrogen Gas

Chemistry 101 Generating Hydrogen Gas Chemistry 101 Generating Hydrogen Gas Objectives To experimentally verify the molar volume of hydrogen gas at STP To gain experience in collecting gas over water Discussion The molar volume of a gas is

More information

Oxygen Give and Take. Correlation to National Science Education Standards

Oxygen Give and Take. Correlation to National Science Education Standards Chemistry and Environmental Sciences Oxygen Give and Take Summary This is a series of three activities followed by a worksheet. The concepts taught include gas production (O 2 and CO 2 ), chemical reactions,

More information

EXPERIMENT 13: GAS STOICHIOMETRY

EXPERIMENT 13: GAS STOICHIOMETRY EXPERIMENT 13: GAS STOICHIOMETRY PURPOSE To collect a gas produced in a reaction and compare the volume actually collected to a "target volume". To discover and compensate for assumptions made in the stoichiometric

More information

Experiment 6 Coffee-cup Calorimetry

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

More information

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

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

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

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

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

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

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

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

Honors Chemistry: Unit 6 Test Stoichiometry PRACTICE TEST ANSWER KEY Page 1. A chemical equation. (C-4.4)

Honors Chemistry: Unit 6 Test Stoichiometry PRACTICE TEST ANSWER KEY Page 1. A chemical equation. (C-4.4) Honors Chemistry: Unit 6 Test Stoichiometry PRACTICE TEST ANSWER KEY Page 1 1. 2. 3. 4. 5. 6. Question What is a symbolic representation of a chemical reaction? What 3 things (values) is a mole of a chemical

More information

Physical and Chemical Properties and Changes

Physical and Chemical Properties and Changes Physical and Chemical Properties and Changes An understanding of material things requires an understanding of the physical and chemical characteristics of matter. A few planned experiments can help you

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

The Synthesis of trans-dichlorobis(ethylenediamine)cobalt(iii) Chloride

The Synthesis of trans-dichlorobis(ethylenediamine)cobalt(iii) Chloride CHEM 122L General Chemistry Laboratory Revision 2.0 The Synthesis of trans-dichlorobis(ethylenediamine)cobalt(iii) Chloride To learn about Coordination Compounds and Complex Ions. To learn about Isomerism.

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

Catalase. ***You will be working with hot water, acids and bases in this laboratory*** ****Use Extreme Caution!!!****

Catalase. ***You will be working with hot water, acids and bases in this laboratory*** ****Use Extreme Caution!!!**** AP BIOLOGY BIOCHEMISTRY ACTIVITY #9 NAME DATE HOUR CATALASE LAB INTRODUCTION Hydrogen peroxide (H 2 O 2 ) is a poisonous byproduct of metabolism that can damage cells if it is not removed. Catalase is

More information

Measurement and Calibration

Measurement and Calibration Adapted from: H. A. Neidig and J. N. Spencer Modular Laboratory Program in Chemistry Thompson Learning;, University of Pittsburgh Chemistry 0110 Laboratory Manual, 1998. Purpose To gain an understanding

More information

Micro Mole Rockets Hydrogen and Oxygen Mole Ratio As adapted from Flinn ChemTopic- Labs - Molar Relationships & Stoichiometry

Micro Mole Rockets Hydrogen and Oxygen Mole Ratio As adapted from Flinn ChemTopic- Labs - Molar Relationships & Stoichiometry Micro Mole Rockets Hydrogen and Oxygen Mole Ratio As adapted from Flinn ChemTopic- Labs - Molar Relationships & Stoichiometry Introduction The combustion reaction of hydrogen and oxygen is used to produce

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

In this experiment, we will use three properties to identify a liquid substance: solubility, density and boiling point..

In this experiment, we will use three properties to identify a liquid substance: solubility, density and boiling point.. Identification of a Substance by Physical Properties 2009 by David A. Katz. All rights reserved. Permission for academic use provided the original copyright is included Every substance has a unique set

More information

Temperature. Number of moles. Constant Terms. Pressure. Answers Additional Questions 12.1

Temperature. Number of moles. Constant Terms. Pressure. Answers Additional Questions 12.1 Answers Additional Questions 12.1 1. A gas collected over water has a total pressure equal to the pressure of the dry gas plus the pressure of the water vapor. If the partial pressure of water at 25.0

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

Unit 6 The Mole Concept

Unit 6 The Mole Concept Chemistry Form 3 Page 62 Ms. R. Buttigieg Unit 6 The Mole Concept See Chemistry for You Chapter 28 pg. 352-363 See GCSE Chemistry Chapter 5 pg. 70-79 6.1 Relative atomic mass. The relative atomic mass

More information

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

Experiment 8 Preparation of Cyclohexanone by Hypochlorite Oxidation

Experiment 8 Preparation of Cyclohexanone by Hypochlorite Oxidation Experiment 8 Preparation of Cyclohexanone by ypochlorite xidation In this experiment we will prepare cyclohexanone from cyclohexanol using hypochlorite oxidation. We will use common household bleach that

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

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. Chapter 10 MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) A gas at a pressure of 10.0 Pa exerts a force of N on an area of 5.5 m2. A) 1.8 B) 0.55

More information

7. 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.

7. 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 information

Experiment 9: Acids and Bases Adapted from: Chemistry, Experimental Foundations, 4th Ed. Laboratory Manual, by Merrill, Parry & Bassow.

Experiment 9: Acids and Bases Adapted from: Chemistry, Experimental Foundations, 4th Ed. Laboratory Manual, by Merrill, Parry & Bassow. Chem 121 Lab Clark College Experiment 9: Acids and Bases Adapted from: Chemistry, Experimental Foundations, 4th Ed. Laboratory Manual, by Merrill, Parry & Bassow. Content Goals: Increase understanding

More information

Enzyme Action: Testing Catalase Activity 50 Points

Enzyme Action: Testing Catalase Activity 50 Points Names: LabQuest Enzyme Action: Testing Catalase Activity 50 Points 6A Many organisms can decompose hydrogen peroxide (H 2 O 2 ) enzymatically. Enzymes are globular proteins, responsible for most of the

More information

Calibration of Volumetric Glassware

Calibration of Volumetric Glassware CHEM 311L Quantitative Analysis Laboratory Revision 2.3 Calibration of Volumetric Glassware In this laboratory exercise, we will calibrate the three types of glassware typically used by an analytical chemist;

More information

Extraction: Separation of Acidic Substances

Extraction: Separation of Acidic Substances Extraction: Separation of Acidic Substances Chemists frequently find it necessary to separate a mixture of compounds by moving a component from one solution or mixture to another. The process most often

More information

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

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

More information

Materials 10-mL graduated cylinder l or 2-L beaker, preferably tall-form Thermometer

Materials 10-mL graduated cylinder l or 2-L beaker, preferably tall-form Thermometer VAPOR PRESSURE OF WATER Introduction At very low temperatures (temperatures near the freezing point), the rate of evaporation of water (or any liquid) is negligible. But as its temperature increases, more

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

Problem Solving. Stoichiometry of Gases

Problem 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 information

Determination of the Empirical Formula of Magnesium Oxide

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

More information

Paper Chromatography: Separation and Identification of Five Metal Cations

Paper Chromatography: Separation and Identification of Five Metal Cations Paper Chromatography: Separation and Identification of Five Metal Cations Objectives Known and unknown solutions of the metal ions Ag +, Fe 3+, Co 2+, Cu 2+ and Hg 2+ will be analyzed using paper chromatography.

More information

Enzyme Action: Testing Catalase Activity

Enzyme Action: Testing Catalase Activity Enzyme Action: Testing Catalase Activity Experiment 6A Many organisms can decompose hydrogen peroxide (H 2 O 2 ) enzymatically. Enzymes are globular proteins, responsible for most of the chemical activities

More information

Experiment 1: Measurement and Density

Experiment 1: Measurement and Density Experiment 1: Measurement and Density Chemistry 140 Learning Objectives Become familiar with laboratory equipment and glassware Begin to see the link between measurement and chemical knowledge Begin to

More information

Enzyme Action: Testing Catalase Activity

Enzyme Action: Testing Catalase Activity Enzyme Action: Testing Catalase Activity Experiment 6A Many organisms can decompose hydrogen peroxide (H 2 O 2 ) enzymatically. Enzymes are globular proteins, responsible for most of the chemical activities

More information

BLOWING UP BALLOONS, chemically

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

More information

DYES AND DYEING 2003 by David A. Katz. All rights reserved. Permission for classroom use provided original copyright is included.

DYES AND DYEING 2003 by David A. Katz. All rights reserved. Permission for classroom use provided original copyright is included. DYES AND DYEING 2003 by David A. Katz. All rights reserved. Permission for classroom use provided original copyright is included. Dyeing of textiles has been practiced for thousands of years with the first

More information

Building Electrochemical Cells

Building Electrochemical Cells 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 voltaic cells and compare the data with the

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

CHM220 Addition lab. Experiment: Reactions of alkanes, alkenes, and cycloalkenes*

CHM220 Addition lab. Experiment: Reactions of alkanes, alkenes, and cycloalkenes* CM220 Addition lab Experiment: Reactions of alkanes, alkenes, and cycloalkenes* Purpose: To investigate the physical properties, solubility, and density of some hydrocarbon. To compare the chemical reactivity

More information

Measuring volume of gas produced Measuring precipitation (because sulphur is produced) e.g. look for X to disappear Measure mass lost

Measuring volume of gas produced Measuring precipitation (because sulphur is produced) e.g. look for X to disappear Measure mass lost Introduction My investigation is about the rate of reaction. A rate of reaction is defined as how fast or slow a reaction takes place. For example, the oxidation of iron under the atmosphere is a slow

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

Synthesis of Aspirin and Oil of Wintergreen

Synthesis of Aspirin and Oil of Wintergreen Austin Peay State University Department of hemistry hem 1121 autions Purpose Introduction Acetic Anhydride corrosive and a lachrymator all transfers should be done in the vented fume hood Methanol, Ethanol

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

Chapter 3 Student Reading

Chapter 3 Student Reading Chapter 3 Student Reading If you hold a solid piece of lead or iron in your hand, it feels heavy for its size. If you hold the same size piece of balsa wood or plastic, it feels light for its size. The

More information

Catalytic Activity of Enzymes

Catalytic Activity of Enzymes Catalytic Activity of Enzymes Introduction Enzymes are biological molecules that catalyze (speed up) chemical reactions. You could call enzymes the Builders and Do-ers in the cell; without them, life could

More information

Desalination of Sea Water E7-1

Desalination 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 information

Partner: Jack 17 November 2011. Determination of the Molar Mass of Volatile Liquids

Partner: Jack 17 November 2011. Determination of the Molar Mass of Volatile Liquids Partner: Jack 17 November 2011 Determination of the Molar Mass of Volatile Liquids Purpose: The purpose of this experiment is to determine the molar mass of three volatile liquids. The liquid is vaporized

More information

Physical Changes and Chemical Reactions

Physical Changes and Chemical Reactions Physical Changes and Chemical Reactions Gezahegn Chaka, Ph.D., and Sudha Madhugiri, Ph.D., Collin College Department of Chemistry Objectives Introduction To observe physical and chemical changes. To identify

More information

Vitamin C Content of Fruit Juice

Vitamin C Content of Fruit Juice 1 Vitamin C Content of Fruit Juice Introduction Vitamin C Vitamins are organic compounds that have important biological functions. For instance, in humans they enable a variety of enzymes in the body to

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

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

Experiment 13H THE REACTION OF RED FOOD COLOR WITH BLEACH 1

Experiment 13H THE REACTION OF RED FOOD COLOR WITH BLEACH 1 Experiment 13H FV 1/25/2011(2-run) THE REACTION OF RED FOOD COLOR WITH BLEACH 1 PROBLEM: Determine the rate law for the chemical reaction between FD&C Red Dye #3 and sodium hypochlorite. LEARNING OBJECTIVES:

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

Kinetic Theory of Gases. 6.1 Properties of Gases 6.2 Gas Pressure. Properties That Describe a Gas. Gas Pressure. Learning Check.

Kinetic Theory of Gases. 6.1 Properties of Gases 6.2 Gas Pressure. Properties That Describe a Gas. Gas Pressure. Learning Check. Chapter 6 Gases Kinetic Theory of Gases 6.1 Properties of Gases 6.2 Gas Pressure A gas consists of small particles that move rapidly in straight lines. have essentially no attractive (or repulsive) forces.

More information

Percentage of Water in Popcorn

Percentage of Water in Popcorn Skills Practice DATASHEET FOR IN-TEXT LAB Percentage of Water in Popcorn Popcorn pops because of the natural moisture inside each kernel. When the internal water is heated above 100 C, the liquid water

More information

Making Biodiesel from Virgin Vegetable Oil: Teacher Manual

Making Biodiesel from Virgin Vegetable Oil: Teacher Manual Making Biodiesel from Virgin Vegetable Oil: Teacher Manual Learning Goals: Students will understand how to produce biodiesel from virgin vegetable oil. Students will understand the effect of an exothermic

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

PRE-LAB FOR YEAST RESPIRATION AND FERMENTATION

PRE-LAB FOR YEAST RESPIRATION AND FERMENTATION PRE-LAB FOR YEAST RESPIRATION AND FERMENTATION PURPOSE: To identify the products of yeast cultures grown under aerobic and anaerobic conditions STUDENTS' ENTERING COMPETENCIES: Before doing this lab, students

More information

The volume of a penny will be calculated from its mass and density.

The volume of a penny will be calculated from its mass and density. Measurement and Density In science a key concern is the quantities involved in chemical processes. These amounts can be directly measured or calculated from other measurements. A measurement consists of

More information

Distillation of Alcohol

Distillation of Alcohol CHEM 121L General Chemistry Laboratory Revision 1.6 Distillation of Alcohol To learn about the separation of substances. To learn about the separation technique of distillation. To learn how to characterize

More information

Determination of a Chemical Formula

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

More information

Chemical Equations & Stoichiometry

Chemical Equations & Stoichiometry Chemical Equations & Stoichiometry Chapter Goals Balance equations for simple chemical reactions. Perform stoichiometry calculations using balanced chemical equations. Understand the meaning of the term

More information

CHEM 36 General Chemistry EXAM #1 February 13, 2002

CHEM 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 information

Whoosh Bottle Safe Laboratory Practices

Whoosh Bottle Safe Laboratory Practices E-Learning Introduction Whoosh Bottle Safe Laboratory Practices Teach essential safety precautions relative to combustion, flammability, and the fire triangle. Publication No. 95010 Concepts Flammable

More information

Chapter 8 - Chemical Equations and Reactions

Chapter 8 - Chemical Equations and Reactions Chapter 8 - Chemical Equations and Reactions 8-1 Describing Chemical Reactions I. Introduction A. Reactants 1. Original substances entering into a chemical rxn B. Products 1. The resulting substances from

More information

H H H O. Pre-Lab Exercises Lab 6: Organic Chemistry. Lab 6: Organic Chemistry Chemistry 100. 1. Define the following: a.

H H H O. Pre-Lab Exercises Lab 6: Organic Chemistry. Lab 6: Organic Chemistry Chemistry 100. 1. Define the following: a. Lab 6: Organic hemistry hemistry 100 1. Define the following: a. ydrocarbon Pre-Lab Exercises Lab 6: Organic hemistry Name Date Section b. Saturated hydrocarbon c. Unsaturated hydrocarbon 2. The formula

More information

Rajesh Swaminathan. March 13, 2005

Rajesh Swaminathan. March 13, 2005 Chemistry 12 IB Corrosion of Iron Rajesh Swaminathan March 13, 2005 1 Planning A 1.1 Aim The aim of the experiment is to investigate factors that affect the rate of corrosion of iron. More specifically,

More information

IB Chemistry. DP Chemistry Review

IB Chemistry. DP Chemistry Review DP Chemistry Review Topic 1: Quantitative chemistry 1.1 The mole concept and Avogadro s constant Assessment statement Apply the mole concept to substances. Determine the number of particles and the amount

More information

Sugar or Salt? Ionic and Covalent Bonds

Sugar or Salt? Ionic and Covalent Bonds Lab 11 Sugar or Salt? Ionic and Covalent Bonds TN Standard 2.1: The student will investigate chemical bonding. Have you ever accidentally used salt instead of sugar? D rinking tea that has been sweetened

More information

Module 5: Combustion Technology. Lecture 34: Calculation of calorific value of fuels

Module 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 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

Metalloids will also react with oxygen. Upon reaction with oxygen silicon forms silicon dioxide, the main component of sand.

Metalloids will also react with oxygen. Upon reaction with oxygen silicon forms silicon dioxide, the main component of sand. The Preparation and Properties of xygen Reading assignment: Chang, Chemistry 10 th edition, pp. 135-141. Goals We will observe the thermal decomposition of several oxygen-containing compounds called oxides.

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