1. Determination of the formula of a compound

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AP Chemistry

General Labs that should be completed for the AP

1. Determination of the formula of a compound

•Empirical Formula/Molecular Formula

•Zumdahl Chapter 1

•Sample Lab: Determine the empirical formula of magnesium oxide by heating pure magnesium over flame.

•Skills/concepts to master: proper procedures for using crucible and Bunsen burners, how to find the empirical formula and its relationship to the molecular formula

Source: http://www.mrdamon.com/experiments/2sp/ magensium_burning/

2. Determination of the percentage of water in a hydrate

• Formula of hydrate; use of heat to produce anhydrous salt

• Zumdahl Chapter 3

• Sample Lab: Find the number of molecules of water that accompanies each molecule of

Epsom salt (magnesium sulfate)*

• Skills/concepts to master: use of burner and crucible, use of lab scale, calculation of hydrate formula

Source: http://www.chem.iastate.edu/group/

Greenbowe/sections/projectfolder/gr aphics/empiricalformulaimage.jpg

http://www.chemmybear.com/groves/images/demos/hydrate

1.jpg

3. Determination of molar mass by vapor density

• Dumas method; ideal gas formula

• Zumdahl Chapter 5

• Sample lab: Measure the molecular weight of an unknown pure liquid by a simplified procedure similar to the Dumas method*

• Skills/concepts to master: Proper method for measuring volume, pressure, and temperature; how molecular weight can be incorporated into the ideal gas formula; how vapor pressure is involved; relationship between volume, pressure, molar mass, and temperature

http://www.chem.uh.edu/freshman/Labs/Chem111x/Exp_07.htm

4. Determination of molar mass by freezing-point depression

• Colligative properties; boiling point elevation, freezing point depression

• Zumdahl chapter 11

• Sample lab: Find the molar mass of KNO3 by using freezing-point depression*

• Skills/concepts to master: measuring and comparing the boiling points of known concentrations of two solutions; measure and compare the freezing points of known concentrations of two other solutions; calculate the molecular mass of the solutes from your boiling point and freezing point data and compare with their theoretical masses

http://www.chem.umass.edu/~botch/Chem11

2S05/Chapters/Ch14/VPLoweringBPElevatio n.jpg

5. Determination of molar volume of a gas

• Standard Temperature and Pressure; volume of gas at STP

• Chapter 5

• Sample lab: Use balloons and dry ice to determine the molar volume of carbon dioxide at

STP by making three mass measurements and recording the temperature and atmospheric pressure

• Skills/concepts to master: The concept of buoyancy, measuring pressure and temperature; gas volume and its relationship to the mole

http://nbsp.sonoma.edu/resources/images/2003/physical/07_0

2_03/pages/balloon1_dry_ice.html

6. Standardization of a solution using a primary standard

• Standardization; titration

• Chapter 14

• Sample lab: Use titration to standardize a sodium hydroxide solution

• Skills/concepts to master: proper method for titration; using titration to find concentrations/formulas

http://www.adrian.ed

u/chemistry/th/Someli nks/Spages/jfakult/P hoto.jpg

7. Determination of concentration by acid-base titration, including a weak acid or a weak base

• Titration; stoichiometry; weak acid and weak base titration versus strong acid/base titration

• Chapter 15

• Sample lab: “Is Household Vinegar Really

5%?” *

• Skills/concepts to master: vinegar as a weak acid, titration of weak acid/base

http://www.usm.maine.edu/chy/manuals/114/text/ABTitr.html

8. Determination of concentration by oxidation-reduction titration

• Redox reactions; redox in titration

• Chapter 15

• Sample Lab: “Is it Really 3% Hydrogen

Peroxide?”*

• Skills/concepts to master: stoichiometry of a reaction; redox reaction and its relationship to titration; the concentration of hydrogen peroxide

http://gakuen.gifunet.ed.jp/~contents/kou_nougyou

/jikken/SubShokuhin/03/index.ht

ml

9. Determination of mass and mole relationship in a chemical reaction

• Mass; mole

• Chapter 1

• Sample Lab: Calculate the moles after measuring the masses of NaHCO3 and

NaCl

• Skills/concepts to master: how to use stoichiometry to determine the mass and mole relationships of the solid reactant and product

10. Determination of an equilibrium constant for a chemical reaction

• Rate of reaction; equilibrium constant

• Chapter 15

• Sample lab: determine the equilibrium constant for a reaction using spectrophotometric techniques

• Skills/concepts to master: use of the spectrophotometer, how to measure concentrations of products and reactants, how to find the equilibrium constant

http://www.chem.ufl.edu/~itl/4411/colligative/lec_i.html

11. Determination of appropriate indicators for various acid-base titrations; pH determination

• pH; indicators and their functions

• Chapter 15

• Sample lab: “ EquilibriumHydrolysis”*

• Skills/concepts to master: results of strong/weak base/acid combinations; use of appropriate solution indicators

http://www.bbc.co.uk/schools/gcsebite size/science/edexcel/chemicalreaction s/makingsaltsrev2.shtml

12. Determination of the rate of reaction and its order*

•Rate of reaction: change in concentration of a reactant or product per unit time.

•Zumdahl Chapter 12

•Sample Lab: Determine the order of an iodine clock reaction with respect to H2O2

•Skills/concepts to master: how to find the order (and overall order) of the reaction, how to determine the reaction constant, how to graph the reaction orders

Source: http://jchemed.chem.wisc.edu/jc esoft/cca/cca3/STILLS/CLOCK

RX/CLOCK4/64JPG48/10.JPG

13. Determination of enthalpy change associated with a reaction

•Enthalpy: change in heat of reactionendothermic/ exothermic

•Zumdahl Chapter 6

•Sample Lab: Determine the change in enthalpy for the reaction of magnesium metal with hydrochloric acid

•Skills/concepts to master: how to measure enthalpy change for reaction and to see whether it is exothermic or endothermic; how to use a calorimeter

Source: http://www.chem.queensu.ca/PROGRAMS/UG/Firstyearlabs/apsc100/calori metry_files/image004.gif

14. Separation and qualitative analysis of cations and anions*

•Cation-positive ion; Anion- negative ion; can result in insoluble precipitates

•Zumdahl Chapter 4

•Sample Lab: Determine which combination of substances will produce a precipitate reaction

•Skills/concepts to master: the general solubility rules; how to describe precipitation reactions by writing net ionic equations

Silver Chloride solution: AgCl

Source: http://genchem.chem.wisc.edu/ demonstrations/Images/15prec ip/agcldissovesinxs.jpg

15. Synthesis of a coordination compound and its chemical analysis*

•Complex ion: has a metal ion at its center with a number of other molecules and ions surrounding it

•Zumdahl Chapter 15

•Sample Lab: Determine the effects of varying concentration of reactants and the reactions between ammonium hydroxide and copper chloride

•Skills/concepts to master: how to form copper hydroxide or copper ion ammonia complex; the effect of acid and base on the copper amine formation

Copper Amine Complex Formation

The well at the left contains copper chloride and water.

Beginning from the right, the wells contain increasing amounts of aqueous ammonia solution.

Source: http://dwb4.unl.edu/dwb/Meetings/Oct-8-

99/CopperAmmoniaI.GIF

16. Analytical gravimetric determination

•The quantitative determination of a substance by precipitation followed by isolation and weighing of the precipitate is called gravimetric analysis

•Zumdahl Chapter 1

•Sample Lab: Determine the mass of chloride in a solution after precipitation the chloride with silver and weighing the silver chloride

•Skills/concepts to master: how to use the laboratory scale efficiently; how to form the AgCl precipitate

Source: http://wulfenite.fandm.edu/labt ech/images/Heating.JPG

17. Colorimetric or spectrophotometric analysis

•Spectrophotometric techniques are used to measure the concentration of solutes in solution by measuring the amount of light that is absorbed by the solution in a cuvette placed in the spectrophotometer.

•Zumdahl Chapter 20

•Sample Lab: Determine the “absorption spectrum” of permanganate by using a spectrophotometer

•Skills/concepts to master: how to use and analyze a spectrophotometer, how to determine concentration of a solution

Source: http://www.rsc.org/ej/AN/2000/ a909345a/a909345a-f7.gif

18. Separation by Chromotography

•Chromatography is the separation of mixtures. It involves passing a mixture dissolved in a "mobile phase" through a stationary phase, which separates the substance to be measured from other molecules in the mixture and allows it to be isolated.

•Zumdahl Chapter 1

•Sample Lab: to separate the different pigments of a plant using acetone and filter paper

•Skills/concepts to master: the purpose of chromatography; the different pigments of a plant; the wavelengths of the various pigments

Source: http://www.msu.edu/course/lbs/1

45/luckie/inquiries2002/image00

2.jpg

19. Preparations and properties of buffer solutions

•Buffer solutions: resist change in pH upon small additions of acids/bases

•Zumdahl Chapter 15

•Sample Lab: create a buffer solution with

HCl and NaOH

•Skills/concepts to master: how to make an ideal buffer solution; the resistance in change of pH for buffers; use of a buffer

Source: http://alpha.chem.umb.edu/chemistr y/ch118/labs/BuffersNew.pdf

20. Determination of electrochemical series

•Standard reduction potential; redox reaction that can be broken into two half reactions: the oxidation occurring at the anode and the reduction occurring at the cathode.

•Zumdahl Chapter 17

•Sample Lab: build several electrochemical cells using metal electrodes

•Skills/concepts to master: the flow of electron current in a galvanic cell; redox reactions in terms of a galvanic cell; how to build a galvanic cell

Source: http://upload.wikimedia.org/wikipedia/en/thumb/3/39/Electroche mCell.png/250px-ElectrochemCell.png

21. Measurements using electrochemical cells and electroplating

•Electroplating is the process of using electrical current to coat an electrically conductive object with a relatively thin layer of metal.

•Zumdahl Chapter 17

•Sample Lab: to use electroplating to plate copper onto a subject such as a nail

•Skills/concepts to master: how to perform electroplating; how to write the respective redox half reactions; how to differentiate between the anode and cathode

Source: http://membership.acs.org/C/Chi cago/statefair/CD-

2006/ChmShort/photos/Cunails1.jpg

Source: http://genchem.chem.wisc.ed

u/demonstrations/Images/17e lectro/copperplate.jpg

22. Synthesis, purification, and analysis of an organic compound

•An organic compound is any compound that contains carbon.

•Zumdahl Chapter 22

•Sample Lab: to identify different organic compounds in plants

•Skills/concepts to master: the locations of the organic compounds in plants; the various uses of organic compounds; how to write the organic formulas

Source: http://botit.botany.wisc.edu/courses/b otany_130/Organic_compounds/Lab.

html

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