Instructor’s Copy
Lab Worksheet – Polar Water
Observations:
Substance
Sodium chloride
Table 1: Compound Solubility in Water
Formula
Physical State
NaCl
Solid
Solubility in Water
Soluble
Glycerin
C3H8O3
Liquid
Miscible
Sucrose
C12H22O11
Solid
Soluble
Sodium thiosulfate
N2S2O3
Solid
Soluble
Calcium carbonate
CaCO3
Solid
Insoluble
Hexane
C6H14
Liquid
Insoluble
Potassium sulfate
K2SO4
Solid
Soluble
Ethanol
C2H5OH
Liquid
Soluble
Kerosene*
C9-C15 hydrocarbon
Liquid
Insoluble
Analyses and Conclusions:
1. Polar and ionic substances generally dissolve in water; nonpolar substances do not. Explain.
The slight charge of the polar water molecule is attracted to the charged particles in the
polar and ionic substances. This attraction helps pull the substances apart to help them
dissolve.
2. Based on the fact that calcium carbonate is an ionic compound, you may be puzzled by your
experimental results for this compound. Propose an explanation for the solubility of calcium
carbonate.
Various answers may be given but the most common is that the calcium and carbon form
a strong bond so they do not pull apart easily.
3. What basis can you use to decide whether the liquids tested are polar or nonpolar? Which of the
liquid substances tested are polar? Which are nonpolar?
In general, if it dissolved in the water, it is polar. For polar, students may answer ethanol,
potassium sulfate, sodium chloride, and sodium thiosulfate. For nonpolar, kerosene,
hexane, and calcium carbonate. Accept either one for glycerin.