Solutions and Solubility Problems

Some water is added to an empty glass. A sugar cube is then dropped in and dissolved. The water is the (a)   and the sugar is the ​ (b)   .

• solvent
• solute
• solution
• acid
• base

Answer explanation

Generally, the substance present in smaller

proportions is the solute and the one present

in greater proportions is the solvent. The

total mixture is a solution.

What happens to a solution of KNO₃ that is saturated at 50°C when it is cooled quickly to 10°C?

• Extra solute falls out of solution

• The solution is not changed

• The solution becomes unsaturated

• The solution becomes supersaturated

Answer explanation

When decreasing the temperature QUICKLY, the solubility of the salt will decrease, causing the extra solute to recrystallize out of the solution.

How many grams of KNO₃ will dissolve in 100 grams of water at 50°C to make a saturated solution?

• 20 g

• 10 g

• 60 g

• 50 g

Answer explanation

Read the graph by locating the provided temperature. Trace the temperature line up to the curve. Read the mass of the solute that intersects the curve perpendicular to the temperature line.

How many grams of KNO₃ can dissolve in 300 grams of water at 50 °C?

• 60 g

• 50 g

• 20 g

• 10 g

Answer explanation

The graph provides the amount of the solute per 100 g of water. Since the mass of water is tripled, so must the mass of the solute to create a saturated solution.

A solution contains 15.0 g of compound D in 100 g of water at 60°C. This solution would be ______.

Answer explanation

The line on the solubility curve is a saturated solution. At 60°C, a saturated solution would contain 22 g of the solute. This solution is unsaturated because it can still dissolve more solute.

A researcher dissolves 60.00 g of compound E in 100 g of water at 20.0°C. The researcher allows the solution to cool in a refrigerator to 5°C and finds precipitate has formed on the bottom of the beaker. The solution is considered to be ________.

Answer explanation

What mass of NaNO₃ is needed to prepare 225 mL of a 1.55 M solution of NaNO₃?

• 29.6 g

• 0.132 g

• 4.10 g

• 0.244 g

• 12.3 g

A sample containing _____ grams of CaBr₂ are needed to prepare 4.65 L of a 7.65 M solution?

How many moles of HCl are present in 40.0 mL of a 0.035 M solution?

• 0.0060 mol HCl

• 0.0014 mol HCl

• 0.012 mol HCl

• 0.0012 mol HCl

A sample containing _____ moles of sodium chloride are there in 250 mL of a 1.20 M solution of NaCl?