Experiment 16A-Polar & Non-Polar Solutes and Solvents

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Name ___________________________
Experiment 16A-Polar & Non-Polar Solutes and Solvents
Purpose: To determine the effects of polar and non-polar solvents on ionic, polar covalent and
non-polar covalent solutes.
Procedure:
Solubility Test on Known Solutes
1. Put on your lab apron and safety goggles.
2. Obtain 6 clean, dry test tubes and place them in a test-tube rack so that you have two
rows of test tubes with three test tubes in each row.
3. Half-fill one set of three test tubes with water at room temperature, and half fill the other
set of three test tubes with paint thinner. Your test tubes should now form a grid that is
similar to the grid in table one.
4. In the first pair of test tubes (one containing water, the other containing paint thinner)
add enough crystals of slat with a pair of tweezers to cover the bottom of the test tubes.
5. Stopper one of these test tubes, and then invert it to agitate the mixture. Turn the test tube
over several times until you are convinced that no further change will take place.
Carefully examine the inside of the test tube for crystals that may get trapped on the
walls. Repeat this agitation process for the second test tube, and then record your
observations for both test tubes in your copy of table 1 in your notebook. (Record
whether or not the solute dissolves.)
6. Repeat Steps 3 and 4 with crystals of sugar in the second pair of test tubes.
7. Repeat Steps 3 and 4 with an iodine crystal in the remaining pair of test tubes. (Note: One
iodine crystal gives better results than several crystals.)
8. Clean up your apparatus according to the reagent disposal instructions.
Mixing Two Liquids
1. Fill a clean test tube one quarter full with water, then add twice as much paint thinner as
water to the same test tube.
2. Stopper the open end of the test tube and agitate the liquids as in Part 1.
3. Examine what happens to the liquids after agitation, and record your observations in your
table 3.
4. Add one Iodine crystal to the test tube and agitate the contents. Make a labeled sketch of
your test tube and its contents.
5. Using a second test tube, repeat steps 1 to 4, but use glycerin in place of paint thinner.
Glycerin is also known as glycerol, or as you will learn in organic chemistry, 1, 2, 3propanetriol. It is a polar liquid.
6. Clean up all apparatus according to the reagent disposal instructions.
7. Before you leave the laboratory, wash your hands thoroughly with soap and water.
Table 1 – Known Solutes with Known Solvents
SOLVENTS
Salt (NaCl)
SOLUTES
Sugar (C12H22O11)
Iodine (I2)
IONIC
POLAR COVALENT
NON-POLAR COVALENT
Water
(Polar Covalent)
Paint Thinner
(Non-Polar Covalent)
Table 3– Mixing Two Liquids
COMBINATIONS OF LIQUIDS
COVALENT TYPES
Water & Paint Thinner
Polar and Non-Polar
Water & Glycerin
Polar and Polar
RESULTS (Observations)
Sketches of Test Tubes with Mixtures of Liquids with Iodine
Test-tube with Paint
Thinner, Water and a
Crystal of Iodine
Test-tube with
Glycerin, Water and
a Crystal of Iodine
Questions:
Part 1:
1.
Polar covalent solvents like _______________ are good at dissolving _______________
solutes like NaCl and polar covalent solutes like _________________, but not good at
dissolving ______ ____________ solutes like ____________________.
2.
Non-polar covalent solvents like ___________________________ are good at dissolving
non-polar covalent solutes like ____________________, but not good at dissolving ionic
solutes like ____________________ or polar covalent solutes like _________________.
Part 2:
3.
Define miscible –
4.
Define immiscible –
4.
Water (polar covalent) and paint thinner ( ________- polar covalent) are
(miscible/immiscible) _____________________________________________________
5.
Water (polar covalent) and glycerin ( ___________ covalent) are
(miscible/immiscible) _____________________________________________________
6.
To summarize all the observations, LIKE dissolves ___ ___ ___ ___. (one word, 4 letters)
7.
Explain why water is effective at dissolving ionic compounds like NaCl. Give a full
explanation with a diagram! (See pages 209-210) of the Student Workbook)
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