Determination of a Chemical Formula

Size: px
Start display at page:

Download "Determination of a Chemical Formula"

Transcription

1 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 4 is composed of 1 titanium and 4 chlorine atoms. Therefore, 1 mole of titanium will combine with 4 moles of chlorine to produce 1 mole of TiCl 4. The molar ratio of titanium to chlorine in the compound is 1 to 4. This can be expressed as a fraction: moles of Ti in compound = = 0.25 moles of Cl in compound 4 Alternatively, we can think about the molar ratio of chlorine to titanium in TiCl 4, which is 4 to 1. This can also be expressed as a fraction: moles of Cl in compound = = 4.0 moles of Ti in compound 1 Suppose you don t know the formula of a particular compound. If you know the molar ratio of two elements in the compound, you can use that ratio to determine the simplest possible formula for the compound. For example, suppose you determined the following ratio in the lab for a compound that is composed of nitrogen and hydrogen: moles of H in a sample of the compound mol = = moles of N in a sample of the compound mol 1 This data could also be expressed as follows, with the moles of N over moles of H instead: moles of N in a sample of the compound mol = = moles of H in a sample of the compound mol 3 From either of these ratios (H over N, or N over H) you know that there are approximately 3 H s for every 1 N in the compound. Therefore, the simplest possible formula for the compound is NH 3. In this experiment you will determine the chemical formula of a compound that is composed of only copper (Cu) and chlorine (Cl). You will not know the formula of this compound ahead of time, but you will be able to determine its formula by determining the number of moles of copper that combine with a given number of moles of chlorine. You will calculate the moles or copper and chlorine from the masses (grams) of copper and chlorine in the compound, which are easily measured in the lab. The prelab sheet provides an example of exactly how this will be done, but uses a compound containing hydrogen and oxygen instead of copper and chlorine.

2 2 Determination of the Chemical Formula of a Compound Containing Copper and Chlorine You will be given a sample of a compound that is known to be composed only of copper and chlorine. More specifically, it is composed of copper ions and chloride ions. To determine the formula of the compound, the first step will be to determine the number of grams of copper and grams of chlorine in the sample of the compound. To determine the masses (in grams) of copper and chlorine in the sample, you will need to separate the copper from the chlorine. This separation will be accomplished by carrying out a chemical reaction in which all of the copper ions in the compound undergo a reaction in which they are converted to solid copper metal. The copper metal can then be filtered out of solution and its mass determined. Below is the reaction that will be carried out to convert the copper ions to copper metal (the reaction is not balanced): Cu ions + Cl - + Al metal Cu metal + Cl - + Al ions from from aluminum will appear compound compound foil as brown particles For the reaction, the compound is dissolved in water and mixed with aluminum metal (pieces of aluminum foil). The copper ions from the compound react with the aluminum foil. Notice that the copper ions are converted to solid copper metal, and the aluminum metal is converted to aluminum ions. Also notice that the chloride ions from the compound do not react they remain unchanged. After the reaction is complete, the brown particles of copper metal that have formed can be filtered out of the solution. The particles will then be dried and their mass determined. Based on that mass, you will be able to determine the formula of the compound, using the calculation steps outlined on the prelab. Conversion of Mass to Moles If you do not remember how to convert a mass (in grams) to moles, use the example below as a guide. Convert grams of zinc to moles of zinc. The molar mass of zinc (65.38 g/mol) can be obtained from the periodic table g of zinc 1 mole of zinc = moles of zinc g Therefore, g of zinc is equivalent to moles of zinc.

3 3 Determination of a Chemical Formula Prelab Name Suppose a certain compound contains only hydrogen and oxygen. Analysis of a 5.00 g sample of this compound revealed that the sample contained 4.44 g of oxygen. How many grams of hydrogen does the sample contain? Show your work here. Convert the grams of oxygen (4.44 g) to moles of oxygen. Show your work below and include units on each number in the calculation. (From the periodic table, oxygen s molar mass is 16 g/mol) Convert the grams of hydrogen (that you calculated first) to moles of hydrogen. Show your work below and include units on each number in the calculation. (From the periodic table, hydrogen s molar mass is 1 g/mol) Now that you know the number of moles of oxygen (O) and the number of moles of hydrogen (H) the 5.00 g sample contained, what is the H to O molar ratio of this compound? Based on this H to O molar ratio, what is the simplest formula of this compound? In today s experiment you will begin with a compound containing only copper and chlorine, and determine the grams of copper in a sample of the compound. Then you will do the same calculations as above in order to determine the simplest formula for the copper/chlorine compound.

4 4 Determination of a Chemical Formula Procedure 1. Weigh out approximately 2.5 g of the copper chloride compound and record the exact mass (all digits from the reading on the balance) on the report sheet. Place it in a 150 ml beaker and add 40 ml of purified water. Stir until the compound is completely dissolved be patient as this may take a few minutes. 2. To the beaker add approximately 0.5 g of aluminum foil which has been cut into small squares. Use a stirring rod to push the foil into the solution if necessary. The reaction should begin to occur immediately and should be obvious. Wait until the reaction ceases and the solution becomes less cloudy (~10 minutes; when most of the bubbling has stopped). While waiting, obtain a Buchner funnel and filter flask from the stockroom. 3. Add 10 ml of 6 M HCl to dissolve the excess aluminum foil that remains. Wait until this reaction ceases, at which point there should be no tiny particles of aluminum remaining. If you can still see particles of aluminum in the solution, ask the instructor for help. You should be able to see a large quantity of brown solid that has precipitated to the bottom of the beaker this is the copper metal (in very fine particles). 4. Obtain 30 ml of acetone in a beaker and set it aside for the next step. Fill your wash bottle with distilled water and set it aside. Place the Buchner funnel into the top of the filter flask, and clamp the neck of the flask to a ring stand so that it doesn t tip over. Then set up a vacuum filtration apparatus by connecting the arm of the filter flask to a water aspirator using one of the heavy hoses from the cabinet under your lab bench. Place a piece of filter paper into the Buchner funnel, making sure that all the holes are covered. Wet the filter paper so that it sticks in place by squirting it with distilled water from your wash bottle. Ask the instructor to check your setup before proceeding with vacuum filtration. 5. Turn on the water aspirator to create a vacuum in the flask this will draw liquid from the Buchner funnel into the flask, and filter out any solid particles in the process. Pour your reaction mixture into the Buchner funnel in order to filter out the solid copper. You must try to get ALL copper particles into the Buchner funnel. If any copper remains stuck to the sides of the beaker, use as much distilled water from your wash bottle as necessary to wash the particles into the funnel. Wash the copper in the Buchner funnel with three additional portions of distilled water (~10 ml each) in order to rinse away any chloride or aluminum ions from the reaction mixture that may remain stuck to the copper.

5 5 6. Break the vacuum by detaching the hose from the arm of the filter flask. Pour about 1/3 of the acetone into the Buchner funnel to cover the copper; allow it to drip through by gravity. Acetone will wash much of the water away from the copper, speeding up the subsequent process of drying the copper. Water evaporates slowly, but acetone evaporates much more quickly. Therefore, you will only have to wait a short period of time for the acetone to evaporate before weighing the dry copper. When all the acetone has dripped out of the Buchner funnel, pour another portion of the remaining acetone into the funnel to cover the copper, and allow it to drip through. Then repeat this process one more time with the last of the acetone. When the last portion of acetone has dripped out of the funnel, re-attach the hose to the arm of the filter flask (be sure the aspirator is turned on to create a vacuum). Allow the vacuum to draw air through the copper in the funnel for a few minutes in order to help the acetone evaporate. 7. Detach the hose from the arm of the filter flask and carefully remove the Buchner funnel from the top of the flask. Transfer the copper to a clean, dry evaporating dish, being careful not to lose any particles of copper in the process. Scrape as much copper as possible off of the filter paper and into the evaporating dish. The filter paper can then be discarded. Label the dish with your name by attaching a piece of tape to the edge. Put the dish in the oven for 15 minutes to dry the copper thoroughly (the oven should be on setting 5, at 110 o C). 8. The liquid in the filter flask can be discarded down the drain. Wash the Buchner funnel and flask and return them to the stock room. Check the copper after it has been in the oven for 15 minutes. When it is dry, it should seem powdery, rather than sticky, when stirred with a glass stirring rod. 9. Allow the dry copper to cool. Then weigh it and record its exact mass on the report sheet. Ask the instructor how to dispose of the copper. Complete the rest of the calculations on the report sheet in order to determine the formula of the compound.

6 6 Determination of a Chemical Formula Report Sheet Name Data 1. Mass of original sample of compound g 2. Mass of copper obtained g Calculations 3. Mass of chlorine in original sample g 4. Moles of copper obtained mol 5. Moles of chlorine in original sample mol 6. Molar ratio of chlorine to copper: moles of Cl / 1 mole of Cu Record the exact number from the calculation. 7. Simplest formula for the compound:

7 7 Determination of a Chemical Formula Postlab Name 1. Circle one answer for each of the following: If you did not let the copper dry thoroughly, how will the apparent mass of copper (line #2) be affected? too high or too low How will the calculated mass of chlorine (line #3) be affected? too high or too low How will the calculated moles of copper (line #4) be affected? too high or too low How will the calculated moles of chlorine (line #5) be affected? too high or too low How will mole ratio of chlorine to copper (line #6) be affected? too many moles of Cl for one mole of Cu or too few moles of Cl for one mole of Cu Finally, based on the answers you circled above, will the formula (line #7) come out correctly for the compound even if you failed to let all the water evaporate from the copper? YES or NO 2. What was the purpose of washing the copper residue with acetone? 3. What was the purpose of adding 6 M HCl in step 3 of the procedure? If you skipped this step with HCl, how would the apparent mass of copper (line #2) be affected? too high or too low How would the calculated mass of chlorine (line #3) be affected? too high or too low

Separation of a Mixture In-Class Prelab NAME

Separation of a Mixture In-Class Prelab NAME 1 Separation of a Mixture In-Class Prelab NAME The amounts of sand, salt, and benzoic acid that will dissolve in 100 g of water at different temperatures: Temperature 0 o C 20 o C 40 o C 60 o C 80 o C

More information

4. Determining the Chemical Formula of an Ionic Compound

4. Determining the Chemical Formula of an Ionic Compound 4. Determining the Chemical Formula of an Ionic Compound What you will accomplish in this experiment You ve learned that compounds are a chemical combination of elements, meaning that they re created when

More information

Recrystallization Introduction Solubility

Recrystallization Introduction Solubility 1 Recrystallization Introduction Solubility Most compounds are more soluble in a given solvent at higher temperatures. As you can see from the data in the table below, the solubilities in water of salt

More information

DETERMINATION of the EMPIRICAL FORMULA

DETERMINATION of the EMPIRICAL FORMULA DETERMINATION of the EMPIRICAL FORMULA One of the fundamental statements of the atomic theory is that elements combine in simple whole number ratios. This observation gives support to the theory of atoms,

More information

5. Determine the limiting reagent and calculate the theoretical yield of a reaction. 6. Calculate percent yield.

5. Determine the limiting reagent and calculate the theoretical yield of a reaction. 6. Calculate percent yield. Stoichiometry The term "stoichiometry" refers to the quantitative relationships between reactants and products in chemical reactions. In a balanced chemical equation, the coefficients (or mole ratios)

More information

Lab 1: Gravimetric Analysis of a Metal Carbonate

Lab 1: Gravimetric Analysis of a Metal Carbonate AP Chemistry Lab Date: Chemist: Lab Write Up Due Date: Lab 1: Gravimetric Analysis of a Metal Carbonate BACKGROUND How do chemists determine the identity of a compound? A large variety of analytical techniques

More information

CHEM 151 CHEMICAL REACTIONS OF COPPER Fall 2008

CHEM 151 CHEMICAL REACTIONS OF COPPER Fall 2008 CHEM 151 CHEMICAL REACTIONS OF COPPER Fall 2008 Fill-in!!! Pre-lab attached (p 9) Lecture Instructor Stamp Here Name Partner Date Before you begin, read the following section in your Laboratory Handbook:

More information

THREE CHEMICAL REACTIONS

THREE CHEMICAL REACTIONS THREE CHEMICAL REACTIONS 1 NOTE: You are required to view the podcast entitled Decanting and Suction Filtration before coming to lab this week. Go to http://podcast.montgomerycollege.edu/podcast.php?rcdid=172

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

Austin Peay State University Department of Chemistry CHEM 1111. Copper Cycle

Austin Peay State University Department of Chemistry CHEM 1111. Copper Cycle Cautions Nitric acid and sulfuric acid are toxic and oxidizers and may burn your skin. Nitrogen dioxide gas produced is hazardous if inhaled. Sodium hydroxide is toxic and corrosive and will cause burns

More information

Stoichiometry: Mass-mass and percent yield in a precipitate reaction

Stoichiometry: Mass-mass and percent yield in a precipitate reaction Stoichiometry: Mass-mass and percent yield in a precipitate reaction Prelab Assignment: You will complete the Title, Purpose, Background information, Storyboard, and BLANK data table portion of your lab

More information

What is the Percent Copper in a Compound?

What is the Percent Copper in a Compound? Lab 9 Name What is the Percent Copper in a Compound? Pre-Lab Assignment Complete this pre-lab on this sheet. This written pre-lab is worth 15% (3 points) of your lab report grade and must be initialed

More information

CSUS Department of Chemistry Experiment 4 Chem.1A

CSUS Department of Chemistry Experiment 4 Chem.1A Name: Section: Experiment 4: Synthesis of Alum Pre-laboratory Assignment (Read through the experiment before starting!) 1. a) What are the strong acid and strong base used in this synthesis? b) What should

More information

Chemistry 151 Last updated Dec Lab 6: Percent Composition and Empirical formulas

Chemistry 151 Last updated Dec Lab 6: Percent Composition and Empirical formulas Chemistry 151 Last updated Dec. 2012 Lab 6: Percent Composition and Empirical formulas Introduction In this lab, you will experimentally determine the percent composition of a copper chloride, which you

More information

Experiment 16 The Solution is Dilution

Experiment 16 The Solution is Dilution Experiment 16 The is Dilution OUTCOMES Upon completion of this lab, the student should be able to proficiently calculate molarities for solutions. prepare a solution of known concentration. prepare a dilute

More information

Structure of caffeine: O CH 3 CH 3

Structure of caffeine: O CH 3 CH 3 1 Extraction of Caffeine Introduction Caffeine Caffeine occurs naturally in tea leaves and coffee beans. Cocoa beans, used to produce chocolate, contain a compound that is nearly identical in structure

More information

General Chemistry Lab Experiment 4. Limiting Reactant

General Chemistry Lab Experiment 4. Limiting Reactant General Chemistry Lab Experiment 4 Limiting Reactant INTRODUCTION Two factors affect the yield of products in a chemical reaction: (1) the amounts of starting materials (reactants) and (2) the percent

More information

Synthesis of a Coordination Compound Containing Iron and Analysis of this Compound Using Redox Methods Prelab

Synthesis of a Coordination Compound Containing Iron and Analysis of this Compound Using Redox Methods Prelab Synthesis of a Coordination Compound Containing Iron and Analysis of this Compound Using Redox Methods Prelab Name Total /10 NOTE: AT THIS POINT YOU WILL ANSWER ALL PRELAB QUESTIONS IN YOUR CARBON COPY

More information

CHM 130 Analysis of Copper Ore for Cu Content

CHM 130 Analysis of Copper Ore for Cu Content CHM 130 Analysis of Copper Ore for Cu Content Introduction: Copper, in various forms, has been mined from the Earth ever since mankind started using metal tools. Early Egyptian civilizations used bronze,

More information

How Can the Percent Composition of a Salt, Sand and Iron Mixture be Determined?

How Can the Percent Composition of a Salt, Sand and Iron Mixture be Determined? Lab 2 Name How Can the Percent Composition of a Salt, Sand and Iron Mixture be Determined? Pre-Lab Assignment This written pre-lab is worth 15% (3 points) of your lab report grade and must be turned in

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

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 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

Experiment 9 Chem 276 Fall Semester 2010 Page 1 of 8. Separation of compounds using acid-base extraction

Experiment 9 Chem 276 Fall Semester 2010 Page 1 of 8. Separation of compounds using acid-base extraction Experiment 9 Chem 276 Fall Semester 2010 Page 1 of 8 Introduction: Separation of compounds using acid-base extraction Organic compounds are generally insoluble in water. Instead, they are soluble in organic

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

DETERMINATION OF THE PERCENT COMPOSITION OF A MIXTURE

DETERMINATION OF THE PERCENT COMPOSITION OF A MIXTURE Chemistry 111 Lab: Percent Composition Page D-3 DETERMINATION OF THE PERCENT COMPOSITION OF A MIXTURE In this experiment you are to determine the composition of a mixture containing unknown proportions

More information

Synthesis of Alum from Aluminum

Synthesis of Alum from Aluminum SYNTHESIS OF ALUM FROM ALUMINUM 53 OBJECTIVES Synthesis of Alum from Aluminum Become more familiar with single-replacement redox reactions Practice mass and volume measurement techniques Calculate the

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

ANALYSIS OF PHOSPHORUS IN PLANT FOOD

ANALYSIS OF PHOSPHORUS IN PLANT FOOD Experiment 10 ANALYSIS OF PHOSPHORUS IN PLANT FOOD Adapted by Ross S. Nord, Eastern Michigan University, from Analysis of Phosphorous in Fertilizer found at http://chem.lapeer.org/chem2docs/phosphateanal.html

More information

FILTRATION TECHNIQUES

FILTRATION TECHNIQUES FILTRATION TECHNIQUES Filtration, the technique used to separate solids from liquids, is the act of pouring a mixture onto a membrane (filter paper) that allows the passage of liquid (the filtrate) and

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

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

SYNTHESIS AND ANALYSIS OF A COORDINATION COMPOUND OF COPPER

SYNTHESIS AND ANALYSIS OF A COORDINATION COMPOUND OF COPPER Chemistry 111 Lab: Synthesis of a Copper Complex Page H-1 SYNTHESIS AND ANALYSIS OF A COORDINATION COMPOUND OF COPPER In this experiment you will synthesize a compound by adding NH 3 to a concentrated

More information

The Reaction of Calcium Chloride with Carbonate Salts

The Reaction of Calcium Chloride with Carbonate Salts The Reaction of Calcium Chloride with Carbonate Salts PRE-LAB ASSIGNMENT: Reading: Chapter 3 & Chapter 4, sections 1-3 in Brown, LeMay, Bursten, & Murphy. 1. What product(s) might be expected to form when

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

ANALYSIS OF CALCIUM CARBONATE TABLETS

ANALYSIS OF CALCIUM CARBONATE TABLETS Experiment 9 ANALYSIS OF CALCIUM CARBONATE TABLETS Prepared by Ross S. Nord, Eastern Michigan University PURPOSE To perform a gravimetric exercise to determine weight percent of active ingredient in a

More information

PHYSICAL AND CHEMICAL CHANGE EXPERIMENT 1

PHYSICAL AND CHEMICAL CHANGE EXPERIMENT 1 PURPOSE To investigate the criteria used to distinguish between physical and chemical changes in matter. 1 DEFINITIONS Chemical property, physical property, chemical change, physical change, conservation

More information

EXPERIMENT 2. Gravimetric Analysis of a Soluble Chloride

EXPERIMENT 2. Gravimetric Analysis of a Soluble Chloride EXPERIMENT 2 Gravimetric Analysis of a Soluble Chloride SAFETY AND LABORATORY TECHNIQUE NOTE Throughout this experiment, avoid getting silver nitrate solution on your hands (or any other part of your body

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

Category 5 points 4 points 3 points 2 points 1 point 0 points Participation Participated fully. Mostly on-task. Safety reminders needed.

Category 5 points 4 points 3 points 2 points 1 point 0 points Participation Participated fully. Mostly on-task. Safety reminders needed. Lab Report Rubric Category 5 points 4 points 3 points 2 points 1 point 0 points Participation Participated fully Mostly on-task Minimal and Safety participation Prelab /10 Observations Data Units & Significant

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

STOICHIOMETRY: The Reaction of Iron with Copper (II) Sulfate

STOICHIOMETRY: The Reaction of Iron with Copper (II) Sulfate STOICHIOMETRY: The Reaction of Iron with Copper (II) Sulfate Introduction In this experiment we will use stoichiometric principles to deduce the appropriate equation for the reaction between metallic iron

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

Chemistry 1215 Experiment #9 Copper and its Compounds

Chemistry 1215 Experiment #9 Copper and its Compounds Chemistry 1215 Experiment #9 Copper and its Compounds Objective The objective of this experiment is to take a piece of copper as efficiently as possible through a series of chemical reactions. The final

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

Experiment 10B DETERMINING THE MOLAR MASS OF A GAS

Experiment 10B DETERMINING THE MOLAR MASS OF A GAS Experiment 10B DETERMINING THE MOLAR MASS OF A GAS FV 3-31-16 MATERIALS: Dry 250 ml Erlenmeyer flask, piece of foil (~3 x 3 ), 800 ml beaker, 500 ml graduated cylinder, iron ring, ring stand, wire gauze,

More information

Dr. Caddell A Cycle of Copper Reactions Chemistry 101. The Law of Conservation of Mass: A Cycle of Copper Reactions

Dr. Caddell A Cycle of Copper Reactions Chemistry 101. The Law of Conservation of Mass: A Cycle of Copper Reactions The Law of Conservation of Mass: A Cycle of Copper Reactions EQUIPMENT You will need one 250 ml beaker, one hot plate, beaker tongs, a 50 ml graduated cylinder, a stirring rod, a wash bottle full of D.I.

More information

Lab 7. Analysis of Hard Water

Lab 7. Analysis of Hard Water Lab 7. Analysis of Hard Water Prelab Assignment Before coming to lab: Use the handout "Lab Notebook Policy" as a guide to complete the following sections of your report for this lab exercise before attending

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

Solution Stoichiometry Quantitative Preparation of Aqueous Solutions

Solution Stoichiometry Quantitative Preparation of Aqueous Solutions Solution Stoichiometry Quantitative Preparation of Aqueous Solutions Introduction Page 1 of 11 In this week s lab, you and your lab partner will apply your prelab calculations to the preparation of aqueous

More information

Purification by Recrystallization

Purification by Recrystallization Experiment 2 Purification by Recrystallization Objectives 1) To be able to select an appropriate recrystallizing solvent. 2) To separate and purify acetanilide by recrystallization. 3) To compare the melting

More information

Titration of Aspirin Tablets

Titration of Aspirin Tablets Titration of Aspirin Tablets In this lab, you will determine the percent purity of two commercially available aspiring tablets using an acid-base titration. In general, an acid and a base react to produce

More information

CHM 130LL: Vinegar Titration

CHM 130LL: Vinegar Titration CHM 130LL: Vinegar Titration In one type of acid-base neutralization reaction, an acid can react with a metal hydroxide base to produce water and a salt: HX (aq) + MOH (aq) H 2 O (l) + MX (aq) (1) acid

More information

This acid is strong. Be careful.

This acid is strong. Be careful. Copper Conversions Lab Name Introduction In this multi-day lab you will start with a sample of copper metal and run several successive reactions which produce different copper compounds. The last reaction

More information

Element of same atomic number, but different atomic mass o Example: Hydrogen

Element of same atomic number, but different atomic mass o Example: Hydrogen Atomic mass: p + = protons; e - = electrons; n 0 = neutrons p + + n 0 = atomic mass o For carbon-12, 6p + + 6n 0 = atomic mass of 12.0 o For chlorine-35, 17p + + 18n 0 = atomic mass of 35.0 atomic mass

More 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

Chapter 6, Lesson 3: Forming a Precipitate

Chapter 6, Lesson 3: Forming a Precipitate Chapter 6, Lesson 3: Forming a Precipitate Key Concepts The ions or molecules in two solutions can react to form a solid. A solid formed from two solutions is called a precipitate. Summary Students will

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

Experiment 8: Synthesis and Analysis of an Inorganic Compound CH3500: Inorganic Chemistry, Plymouth State University

Experiment 8: Synthesis and Analysis of an Inorganic Compound CH3500: Inorganic Chemistry, Plymouth State University Experiment 8: Synthesis and Analysis of an Inorganic Compound CH3500: Inorganic Chemistry, Plymouth State University Adapted from Johnson, R.C. "Convenient procedure for the preparation of potassium trioxalatoferrate(iii),"

More information

Experiment 20 - Acid-Base Titration: Standardization of KOH and Determination of an Acid Solution

Experiment 20 - Acid-Base Titration: Standardization of KOH and Determination of an Acid Solution Experiment 20 - Acid-Base Titration: Standardization of KOH and Determination of an Acid Solution In this experiment, you will determine the precise concentration of a weak acid solution that has an unknown

More information

Continued on next page

Continued on next page 1 Breathalyzer Reaction Introduction A breathalyzer (breath analyzer) is a device for estimating blood alcohol content (BAC) from a breath sample. The invention of the breathalyzer provided law enforcement

More information

CH204 Experiment 2. Experiment 1 Post-Game Show. Experiment 1 Post-Game Show continued... Dr. Brian Anderson Fall 2008

CH204 Experiment 2. Experiment 1 Post-Game Show. Experiment 1 Post-Game Show continued... Dr. Brian Anderson Fall 2008 CH204 Experiment 2 Dr. Brian Anderson Fall 2008 Experiment 1 Post-Game Show pipette and burette intensive and extensive properties interpolation determining random experimental error What about gross error

More information

The Formula Of A Compound

The Formula Of A Compound The Formula Of A Compound Introduction: A compound is a distinct substance composed of two or more elements chemically combined in fixed proportions. Atoms of the elements in a compound are combined in

More information

The Chemistry of Dyes Part I: The Synthesis of Indigo Dye

The Chemistry of Dyes Part I: The Synthesis of Indigo Dye The Chemistry of Dyes Part I: The Synthesis of Indigo Dye Name: Period: PURPOSE: To synthesize indigo dye in preparation for understanding how and why it dyes fabrics THEORY: Organic Chemistry is the study

More information

ALUM FROM WASTE ALUMINUM CANS 2000 by David A. Katz. All rights reserved.

ALUM FROM WASTE ALUMINUM CANS 2000 by David A. Katz. All rights reserved. ALUM FROM WASTE ALUMINUM CANS 2000 by David A. Katz. All rights reserved. INTRODUCTION Modern beverage containers are usually composed of either aluminum, in the form of aluminum cans, or polyethylene

More information

EXPERIMENT 1: MELTING POINTS

EXPERIMENT 1: MELTING POINTS EXPERIMENT 1: MELTING POINTS 1. Prepare a known sample of urea and determine its melting point. (Use a well packed capillary with ~1-2 mm of sample, with a rise in temperature of ~ 1-2 o C per min near

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

Determination of Molecular Mass by Freezing Point Depression

Determination of Molecular Mass by Freezing Point Depression Determination of Molecular Mass by Freezing Point Depression Objectives: To determine the molecular mass of an unknown solid using the colligative property of freezing point depression. Background: When

More information

Molecular Weight of a Volatile Liquid

Molecular Weight of a Volatile Liquid Molecular Weight of a Volatile Liquid One of the important applications of the Ideal Gas Law is found in the experimental determination of the molecular weight of gases and vapors. In order to measure

More information

Titration of Hydrochloric Acid with Sodium Hydroxide

Titration of Hydrochloric Acid with Sodium Hydroxide Cautions: Hydrochloric acid solution is a strong acid. Sodium hydroxide solution is a strong base. Both are harmful to skin and eyes. Affected areas should be washed thoroughly with copious amounts of

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

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

What is a Chemical Reaction?

What is a Chemical Reaction? Lab 8 Name What is a Chemical Reaction? Macroscopic Indications and Symbolic Representations Pre-Lab Assignment This written pre-lab is worth 25% (5 POINTS) of your lab report grade and must be turned

More information

Experiment 18. Determination of an Equilibrium Constant: Solubility of Ca(OH) 2

Experiment 18. Determination of an Equilibrium Constant: Solubility of Ca(OH) 2 Experiment 18 Determination of an Equilibrium Constant: Solubility of Ca(OH) 2 GOALS: This experiment should help you learn more about equilibrium concepts and how these can be applied to solubility. In

More information

ISOLATION OF CAFFEINE FROM TEA

ISOLATION OF CAFFEINE FROM TEA ISLATIN F CAFFEINE FRM TEA Introduction In this experiment, caffeine is isolated from tealeaves. The chief problem with the isolation is that caffeine does not exist alone in the tealeaves, but other natural

More information

Analysis of Vitamin C

Analysis of Vitamin C Analysis of Vitamin C In today's experiment, you will be titrating samples that contain vitamin C with potassium iodate, KIO 3. The KIO 3 is added to the reaction mixture using a buret while stirring constantly

More information

H 2 N NH 2. ethylenediamine (en) phenanthroline (phen) catechol. ethylenediaminetetraacetic acid (EDTA) Cobalt Complexes Spring 2005 NF Page 1 of 6

H 2 N NH 2. ethylenediamine (en) phenanthroline (phen) catechol. ethylenediaminetetraacetic acid (EDTA) Cobalt Complexes Spring 2005 NF Page 1 of 6 Synthesis and Characterization of Cobalt Complexes Adapted from Preparation and Analysis of Two Coordination Complexes of Cobalt, Carnegie Mellon University. For this experiment: 1. Complete the Prelab

More information

PREPARATION AND PROPERTIES OF A SOAP

PREPARATION AND PROPERTIES OF A SOAP (adapted from Blackburn et al., Laboratory Manual to Accompany World of Chemistry, 2 nd ed., (1996) Saunders College Publishing: Fort Worth) Purpose: To prepare a sample of soap and to examine its properties.

More information

Experiment 8. Determination of the Molar Mass of an Unknown Acid by Acid-Base Titration

Experiment 8. Determination of the Molar Mass of an Unknown Acid by Acid-Base Titration Experiment 8. Determination of the Molar Mass of an Unknown Acid by Acid-Base Titration In this experiment you will: Prepare and standardize a solution of sodium hydroxide Determine the molecular weight

More information

General Chemistry I (FC, 09-10) Lab #4: Stoichiometry: The Reaction of Iron with Copper(II) Sulfate

General Chemistry I (FC, 09-10) Lab #4: Stoichiometry: The Reaction of Iron with Copper(II) Sulfate General Chemistry I (FC, 09-10) Introduction In this experiment we will use stoichiometric principles to deduce the appropriate equation for the reaction between metallic iron and a solution of copper(ii)

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

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

SEPARATION OF A MIXTURE OF SAND AND SALT Experiment 12

SEPARATION OF A MIXTURE OF SAND AND SALT Experiment 12 Physical Science 14 SEPARATION OF A MIXTURE OF SAND AND SALT Experiment 12 INTRODUCTION: Most of the materials we encounter in everyday life are not pure substances. Materials such as cement, wood, soil,

More information

Determination of an Empirical Formula and % Composition

Determination of an Empirical Formula and % Composition Chem 110 Lab Clark College Determination of an Empirical Formula and % Composition Percent composition will be discussed in your text, lecture and in lab. This concept is often used to determine how many

More information

Pieces of iron metal appear on the magnesium. Name:

Pieces of iron metal appear on the magnesium. Name: Name: Introduction This lab will let you see examples of synthesis, decomposition, single replacement, and double replacement reactions. The reactions will be microscale, so very small amounts of chemicals

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

Title: Training Lab 1 Chemistry 11100, Fall Use of a balance a balance is used to measure the mass of solids in the chemistry lab.

Title: Training Lab 1 Chemistry 11100, Fall Use of a balance a balance is used to measure the mass of solids in the chemistry lab. Title: Training Lab 1 Chemistry 11100, Fall 2012 Introduction The purpose of this lab is to introduce you to a series of techniques that you will use in chemistry lab. For this lab, you will be using the

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

STOICHIOMETRY II UNIT

STOICHIOMETRY II UNIT STOICHIOMETRY II UNIT Assignment #1 (Conversions with compounds) 1. Convert 1.806 x 10 23 molecules of Cl2 to moles. 2. Convert 1000 molecules of P4O10 to moles. 3. Convert 360 grams of NH3 (ammonia gas)

More information

Chemistry 1215 Experiment #10 The Reaction of Zinc and Iodine: The Combination of Two Elements

Chemistry 1215 Experiment #10 The Reaction of Zinc and Iodine: The Combination of Two Elements Chemistry 1215 Experiment #10 The Reaction of Zinc and Iodine: The Combination of Two Elements Objective The objective of this experiment is to perform a combination reaction by reacting elemental zinc

More information

2 To use calorimetry results to calculate the specific heat of an unknown metal. 3 To determine heat of reaction ( H) from calorimetry measurements.

2 To use calorimetry results to calculate the specific heat of an unknown metal. 3 To determine heat of reaction ( H) from calorimetry measurements. Calorimetry PURPOSE To determine if a Styrofoam cup calorimeter provides adequate insulation for heat transfer measurements, to identify an unknown metal by means of its heat capacity and to determine

More information

Experiment 7 Preparation of 1-Bromobutane

Experiment 7 Preparation of 1-Bromobutane Experiment 7 Preparation of 1-Bromobutane In this experiment you will prepare 1-bromobutane (n-butyl bromide) from n-butanol (1-butanol) using a substitution reaction under acidic conditions. This is an

More information

9. Recrystallization

9. Recrystallization 9. Recrystallization Recrystallization is a very common technique used to purify solids. A material termed impure is a mixture of two or more components, from which only one component is desired. The other

More information

THE SOLUBILITY PRODUCT CONSTANT OF CALCIUM HYDROXIDE

THE SOLUBILITY PRODUCT CONSTANT OF CALCIUM HYDROXIDE THE SOLUBILITY PRODUCT CONSTANT OF CALCIUM HYDROXIDE The solubility product constant of a substance is a special type of equilibrium constant whose values are used to express the solubility of slightly

More information

Figure 1: Experimental Set-up with Leveling Bulb

Figure 1: Experimental Set-up with Leveling Bulb Gas Laws Equipment Set-up and Leveling bulb discussion: A buret will be used to collect our gas product, so we can measure the volume of gas produced accurately. A leveling bulb (a plastic bottle with

More information

Chemical Composition Review Mole Calculations Percent Composition. Copyright Cengage Learning. All rights reserved. 8 1

Chemical Composition Review Mole Calculations Percent Composition. Copyright Cengage Learning. All rights reserved. 8 1 Chemical Composition Review Mole Calculations Percent Composition Copyright Cengage Learning. All rights reserved. 8 1 QUESTION Suppose you work in a hardware store and a customer wants to purchase 500

More information

Ascorbic Acid Titration of Vitamin C Tablets

Ascorbic Acid Titration of Vitamin C Tablets Ascorbic Acid Titration of Vitamin C Tablets Procedure Each Part of lab requires a separate data table. You might want to put each table on a separate page so you can leave room to show equations and calculations.

More information

CHM 130LL: Vinegar Titration

CHM 130LL: Vinegar Titration CHM 130LL: Vinegar Titration Introduction In an acid-base neutralization reaction, an acid reacts with a base to produce water and a salt: HX (aq) + MOH (aq) H 2 O (l) + MX (aq) (1) acid base salt The

More information

SCH 4C Summative - QUANTITATIVE TITRATION - Part 1

SCH 4C Summative - QUANTITATIVE TITRATION - Part 1 SCH 4C Summative - QUANTITATIVE TITRATION - Part 1 PURPOSE: Design a procedure to make a 0.300mol/L solution of NaOH from solid NaOH pellets. MATERIALS: Solid NaOH Electronic Balance Distilled water Safety

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