Chemistry Name

Period

Comparing Solubilities Lab

Background: Compounds fall into three categories: ionic, polar covalent or nonpolar covalent. When

compounds combine they follow the rule of “like dissolves like”.

Materials:

Solvents Solutes 4 small test tubes

Distilled Water Sucrose Sugar (C12H22O11) 4 stoppers

Ethyl Alcohol (C2H5OH) Salt scooper

n-hexane (C6H14) Naphthalene (C10H8) pipette

Calcium Carbonate test tube rack

Procedure A:

1.  Test the solubility of the various solvents in each other. Mix 1 mL of each solvent with 1 mL of the other solvents in three separate test tubes. Record color, clarity, and if the mixture is soluble (S), slightly soluble (SS), or insoluble (I). Record your results in Data Table 1-1 before agitation.

2.  Place a stopper in each test tube. Agitate the test tube, and record the results after agitation Data Table 1-1.

3.  Clean the test tubes well prior to Procedure B.

Procedure B:

1.  Add 1 mL of H2O solvent into each of the four test tubes.

2.  Place a match head’s amount of each solute into the 4 test tubes (only 1 solute per tube).

3.  Record the results in Data Table 1-1 before agitation.

4.  Place a stopper in each test tube and agitate. Record your observations in Data Table 1-1.

5.  Clean the test tubes. Repeat the procedure using the other two solvents.

CAUTION: Hexane is to be disposed in the HAZARDOUS WASTE CONTAINER!

Data Table 1-1: Observations of solutes in solvents

SOLUTES SOLVENTS

SOLVENTS / Sugar / Salt / Naphthalene / CaCO3 / Water / Ethanol / Hexane
Water (no ag.)
w/ agitation
Ethanol (no ag.)
w/ agitation
Hexane (no ag.)
w/ agitation

Sketch:

1.  Write the molecular formula and draw the structural formula for each solvent (3) and each solute (4) used in this experiment.

2.  Label each substance as ionic, polar or nonpolar. If the molecule is polar covalent, show the position of the partial charges (δ+ or δ-) on the molecule.

Conclusion:

1.  Which of the solutes are soluble in hexane? Are these solutes polar or nonpolar? Explain your decision.

2.  Which solvents were soluble in each other?

3.  Which solvent was soluble in the other two? Explain what must be true about the structure of this solvent.

4.  Which of the chemicals used in this experiment do you think are organic? What characteristic(s) of these structures make them organic?

5.  What is the structural difference between a polar and an ionic molecule? Do they behave differently? If so, how does each behave? Explain their behaviors.

6.  Write your conclusion paragraph