Question

austin decides to conduct a science fair experiment to investigate and determine which solvent is the best at dissolving varying types of solutes. austin knows that most compounds will only dissolve in a specific type of solvent. austin collects three solutes including table salt, baking soda, and table sugar. while the three liquids that austin chose to act as solvents are water, alcohol, and club soda. austin begins his investigation by placing 10 ml of each of the liquids into nine separate cups each with one of the three solvents. he then inserts a teaspoon of each solute into their corresponding cup. austins results are shown in the attached graph.
according to austins data, which of the following correctly identifies the best solvent and conclusion of his results (see attached graph)?

c. club soda is the best solvent and therefore must have a low polarity.
a. water is the best solvent and therefore must have a low polarity.
d. club soda is the best solvent and therefore must have a high polarity.
b. water is the best solvent and therefore must have a high polarity.

Explanation:

• First, analyze the solubility data. Water has the most "X" (dissolved) marks among the solvents. So water is the better solvent.
• Table salt (ionic compound), baking soda (ionic compound), and table sugar (polar covalent compound) all dissolve well in water. According to the "like - dissolves - like" principle, polar solvents dissolve polar or ionic solutes. Since these solutes are polar or ionic, a good solvent for them (water) should have high polarity.

Answer:

B. Water is the best solvent and therefore must have a high polarity.