$\frac{6.022 \times 10^{23}\,\text{ions}}{1\,\text{mol}}$

$\text{Osmolarity} = \text{Molarity} \times n$

Question 1

Which of the following best describes osmolarity?

Accepted Answer

Osmolarity is the number of ions per liter of solution.

Question 2

A 0.10 M solution of CaBr$_2$ is prepared. What is the osmolarity of this solution?

Accepted Answer

$0.30\,	ext{osmoles/L}$

Question 3

Which of the following solutions will have the highest concentration of bromide ions?

Accepted Answer

0.10 M CaBr$_2$

Question 4

What is the concentration of hydroxide ions in a 0.350 M solution of gallium hydroxide, Ga(OH)$_3$?

Accepted Answer

$1.05\,	ext{M}$

Question 5

How many moles of chloride ions are present in 500 mL of 1.0 M NaCl solution?

Accepted Answer

$0.25\,	ext{mol}$

Question 6

If you dissolve 58.1 g of AgCl in enough water to make 500 mL of solution, what is the molarity of chloride ions? (Molar mass of AgCl = 143.32 g/mol)

Accepted Answer

$0.406\,	ext{M}$

Question 7

How many milligrams of nitride ions are required to prepare 820 mL of 0.330 M Ba$_3$N$_2$ solution? (Molar mass of N$^{3-}$ = 14.01 g/mol)

Accepted Answer

270.6 mg

Question 8

How many bromide ions are present in 65.5 mL of 0.210 M GaBr$_3$ solution?

Accepted Answer

$1.38 	imes 10^{22}$ ions

Question 9

Which conversion factor would you use to determine the number of ions from molarity and volume?

Accepted Answer

$\frac{6.022 	imes 10^{23}\,	ext{ions}}{1\,	ext{mol}}$

Question 10

A patient receives an intravenous solution containing 0.150 M K$_2$SO$_4$. What is the osmolarity of the solution?

Accepted Answer

$0.450\,	ext{osmoles/L}$

Question 11

Which of the following statements about osmolarity is correct?

Accepted Answer

Osmolarity depends on both the molarity and the number of ions produced per formula unit.

Question 12

A solution contains 0.250 M AlCl$_3$. What is the concentration of chloride ions?

Accepted Answer

$0.750\,	ext{M}$

Question 13

Which of the following compounds will produce the greatest number of ions per mole when dissolved in water?

Accepted Answer

AlBr$_3$

Question 14

If you have 0.120 L of 0.450 M CaCl$_2$ solution, how many moles of Ca$^{2+}$ ions are present?

Accepted Answer

$0.0540\,	ext{mol}$

Question 15

A nurse needs to prepare 500 mL of a solution containing 0.20 M Na$_2$SO$_4$. How many moles of sodium ions are present in the solution?

Question 16

Which of the following is the correct formula to calculate osmolarity from molarity for a compound that dissociates into $n$ ions?

Accepted Answer

$	ext{Osmolarity} = 	ext{Molarity} 	imes n$

Osmolarity and Ion Calculations in Solution

Study Guide - Practice Questions