Applied Chemistry Chemistry 101 Laboratory Manual

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Applied Chemistry Chemistry 101 Laboratory Manual

Transcript Of Applied Chemistry Chemistry 101 Laboratory Manual

Chemistry 101
Applied Chemistry Chemistry 101
Laboratory Manual
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Chemistry 101
Prepared By
Maria Fenyes Edited by
Charles Mallory
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Chemistry 101
Table of Contents
Table of Contents ....................................................................................................................................3 Syllabus ..................................................................................................................................................5 EXPERIMENT 1: The Balance.................................................................................................................7 EXPERIMENT 2: Density....................................................................................................................... 11 EXPERIMENT 3: Determination of the Empirical Formula of a Compound ............................................. 17 EXPERIMENT 4: Table Salt from Baking Soda...................................................................................... 23 EXPERIMENT 5: Analysis of a Mixture of NaHCO3 and NaCl ................................................................ 27 EXPERIMENT 6: Net Ionic Equations .................................................................................................... 33 EXPERIMENT 7: Conductance in Solutions........................................................................................... 43 EXPERIMENT 8: The Activity Series ..................................................................................................... 57 EXPERIMENT 9: Standardization of a Base .......................................................................................... 65 EXPERIMENT 10: Analysis of Vinegar .................................................................................................. 73 EXPERIMENT 11: Stoichiometry Involving a Gas Collected Over Water ................................................ 79 EXPERIMENT 12: Thermochemistry; Heat of Reaction.......................................................................... 85 EXPERIMENT 13: Separation of Cations by Paper Chromatography ................................................... 103 EXPERIMENT 14: Atomic Emission..................................................................................................... 111 EXPERIMENT 15: The preparation and properties of NaHCO3 ............................................................ 129 EXPERIMENT 16: The Effect of Temperature on Solubility .................................................................. 139 EXPERIMENT 17: Chemical Bonding and Molecular Polarity............................................................... 145 EXPERIMENT 18: Crystal Structure .................................................................................................... 153 EXPERIMENT 30: Percentage of Copper in Malachite......................................................................... 164 EXPERIMENT 31: Table Salt from Soda Ash....................................................................................... 170 EXPERIMENT 32: Equivalent Mass Determination in Oxidation­Reduction Reactions.......................... 174 EXPERIMENT 33: Standardization of a Sodium Hydroxide Solution with a Primary Standard .............. 180 APPENDIX I – Electronegativity of The Elements ................................................................................ 188 APPENDIX II – The Periodic Table ...................................................................................................... 190
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Chemistry 101
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Chemistry 101
Syllabus
Activity
Tour of the laboratory, Laboratory Procedures Proper Use of Laboratory Notebook Safety Video Experiment #1: The Balance Periodic Table of the Elements (Video) Check In Experiment #2: Density; Part 1 and Part 2 Video: The Volumetric Pipette Experiment #2: Density; Part 3 Experiment #3: Determination of the Empirical Formula of a Compound Experiment #4: Table Salt from Baking Soda Experiment #5: Analysis of a mixture of Table Salt and Baking Soda Experiment #6: Net Ionic Equations First Laboratory Exam Experiments 1, 2, 3, 4, 5, and the Periodic Table Video You may consult your Laboratory Notebook Experiment #7: Conductance in Solutions Experiment #8: The Activity Series Experiment #9: Standardization of a Base Experiment #10: Analysis of Vinegar Experiment #11: Stoichiometry involving a Gas Collected over water Experiment #12: Thermochemistry Experiment #12: Thermochemistry continued (calculations) Second Laboratory Exam Experiments 6, 7, 8, 9 and 10 You may consult your Laboratory Notebook Experiment #13: Separation of Cations by Paper Chromatography Experiment #14: Atomic Emission Experiment #14: Atomic Emission continued (calculations) Experiment #15: The preparation and properties of NaHCO3 Experiment #15: The preparation and properties of NaHCO3 continued Experiment #16: The Effect of Temperature on Solubility Experiment #17: Chemical Bonding and Molecular Polarity Experiment #18: Crystal Structure Experiment #18: Crystal Structure continued Check out Laboratory Final Experiments 9, 10, 15, 41, 42, Temp and Crystal
You may consult your Laboratory Notebook

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Chemistry 101
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Chemistry 101

PURPOSE:

EXPERIMENT 1: The Balance

1. To learn to use the different types of balances which are available in the laboratory.
2. To learn the capabilities of the different types of balances which are available in the laboratory.
3. To relate the concept of significant numbers to the accuracy of mass and volume measurements.

PRINCIPLES:

One of the most important operations in a chemistry laboratory is the massing of objects. Since chemistry is an exact science, the massing of substances which enter or result from a chemical change must be done with the best possible accuracy.

Balances differ in capacity and accuracy and the type of balance used in a particular experiment depends on the accuracy desired for that experiment.

For rough massings, where an accuracy of 0.1g is required, the platform decigram balance may be used. The centigram balance is conveniently used when an accuracy of 0.01g is required.

Semi­quantitative and some quantitative massing is commonly performed on the milligram balance, which reads to the nearest 0.001g The most accurate balances commonly used in the modern laboratories for accurate quantitative work are the analytical balances. While they are simple to use, they are also the most delicate and expensive.

The reliability of any balance depends upon how it is treated by the user, but special care is required in treating the analytical balance. For long balance life, certain general rules must be observed:

1. Keep the balance clean. Clean up any spills on, in, or near the balance, immediately.
2. Tare (zero) the balance prior to taking any measurements. Wait for the balance to indicate that it has been tarred prior to placing material on the balance.
3. Never place any chemical directly on the balance pan: always use a piece of weighing paper. Liquids must be weighed in a closed container.
4. When an analytical balance is used, the objects being massed should be handled with forceps or crucible tongs.
5. Objects being massed must always be at room temperature to avoid air currents forming which can affect the accuracy of the mass measurements. When using the analytical balance, always make sure that the windows of the balance are closed.

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Chemistry 101
PROCEDURE:

1. Mass of standard mass on an analytical balance:

Obtain a metal strip of known mass from your instructor and record its identification number. Determine its mass on the analytical balance and record the result. The mass you obtain should agree with the posted mass within 0.0005g. Calculate the Percent Error in your measurement by using the following formula:

Experimental Value ­ Theoretical Value PERCENT ERROR = ­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
Theoretical Value

X 100%

Note: Typically the percent error has no sign (+/­); it is typically given as an absolute value.

2. The mass of a Penny:

Using the difference scales available; determine the mass of the same penny. Record these masses and indicate the accuracy in each measurement. State the number of significant figures in each measurement.

3. The density of a metallic cylinder

Obtain a metallic cylinder and record the material it composed of (brass,
copper steel, or aluminum.) Using your ruler, measure the diameter (d) and the height (h) of the metallic cylinder to the nearest 0.1 mm. Calculate the volume of the metallic cylinder using the formula, V = pr2h. (Recall that 2r=d.)

Determine the mass of the cylinder using the centigram balance.
Calculate the density of the metallic cylinder. (Recall that d=m/V.)
Calculate the Percent Error in your density determination knowing that the theoretical values of the cylinder densities are:
Brass: .......................... 8.50 g/cm3 Copper:........................ 8.96 g/cm3 Steel: .......................... 7.86 g/cm3 Aluminum: ................... 2.70 g/cm3

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Chemistry 101

Experiment 1: THE BALANCE REPORT FORM

NAME: _______________________ Date: _________ Partner(s): ____________________

1. Mass of Standard Mass on Analytical Balance

I.D. Number

Experimental Mass (g)

Theoretical Mass (g)

% Error

2. Mass of Penny

Balance Decigram Centigram Milligram

Mass (g)

Number of Significant
Figures

Number of Certain Digits

Number of Uncertain
Digits

Uncertainty (+/­) ___ g

3. Density of a Metallic Object

Type of Object: ____________________

Diameter: ________ (cm) Radius: _________ (cm) Volume: _________ (cm3)

Height: __________ (cm)

Mass: ___________ (g)

Experimental Density: _______ (g/cm3)
Theoretical Density: ________ (g/cm3)
% Error ___________________% (show your work):

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Chemistry 101
Questions: 1. Good laboratory techniques should provide you with a percent error of less than five (5) percent. If you obtained an error greater than five (5) percent, explain below what was the source of this error below. (If your error was less than five (5) percent, write “N/A” in the space provided.)
2. If an analytical balance is available, why would you ever use the centigram balance?

3. Which of the balances used provided the greatest number of significant digits for mass of the penny?

Known Masses for Part 1
K1 – 1.1877 g K2 – 0.9824 g K3 – 2.0557 g K4 – 2.0675 g K5 – 2.3550 g K6 – 1.5289 g K7 – 1.5957 g K8 – 1.2437 g K9 – 1.6022 g K10 – 1.4881 g K11 – 1.8690 g K12 – 1.6382 g K13 – 1.9364 g K14 – 1.5274 g K15 – 1.6186 g K16 – 1.2153 g K17 – 1.6696 g K18 – 2.0222 g K19 – 1.7287 g K20 – 1.9237 g

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BalanceMassAccuracyCylinderBalances