Solutions self test

Self Test on Solutions

Short essay questions

1.

Explain why water is such a good solvent for polar compounds and ionic compounds.

2.

What relationship is there between Henry's law and the concentration of dissolved gases in the blood? When the partial pressure of oxygen is 159 mm Hg the concentration of dissolved oxygen in the blood can be 0.44 g/ 100 mL of blood. What will happen to the concentration of dissolved oxygen if the oxygen pressure goes down to 56 mm Hg? Why are people with breathing problems placed in an oxygen rich atmosphere?

3.

A person's health is connected to the electrolyte balance in their body. Which of the following cations has the highest concentration in blood plasma? Na⁺, Ca²⁺, K⁺, Mg²⁺.

The inorganic anions Cl^1-, HCO^3-, SO₄^2-, and HPO₄^2- are also present in plasma. The concentrations of these anions do not equal the concentrations of the cations. How is the electrical balance maintained if these ions do not cancel each other?

Multiple choice

1.

A solution of electrolytes will conduct electricity.

a. true

b. false

2.

Which of the following is the most concentrated solution?

a. a mixture of 4000 mL of water and 2 mols NaOH

b. a mixture of 2000 mL of water and 2 mols of HCl

c. a mixture that gives 2000 mL of solution containing 4 mols of NH₃

d. a mixture that gives a solution of 2000 mL containing 6 mols of NH₃

3.

Henry's law predicts which of the following?

a. the concentration of dissolved acid in a solution

b. the concentration of dissolved gas in a solution

c. the concentration of dissolved base in a solution

d. the concentration of acid needed to neutralize a base

4.

Water is the solute in which of the following mixtures?

a. 100 mL of water and 20 grams of NaCl

b. 100 mL of water and 200 mL of ethanol

c. 1000 mL of water and 3 mols of NaOH

d. 2 liters of aqueous solution containing 40 grams of NaOH

5.

The amount of dissolved gas in a solution will generally .......

a. increase when the pressure of the gas decreases

b. decrease when the pressure of the gas decreases

c. decrease when the temperature of the solution decreases

d. not change with pressure

6.

Which of the following is a nonelectrolyte?

a. NaCl

b. HCl

c. NaHCO₃

d. CH₃OH

7.

How many mols of CaCl₂ are dissolved in 250 mL of a 0.30 M CaCl₂ solution?

1 mol CaCl₂ = 111 g CaCl₂

a. (0.250)(0.30)

b. (0.250) / (0.30)

c. (0.30) / (0.250)

d. (0.250) x (111) / 0.30

8.

Which of the following statements is not true?

a. all solutions are colorless

b. suspensions are not transparent

c. all the particles in a solution are atomic or molecular in size

d. all solutions are homogeneous

9.

How many mols of HCl are dissolved in 60.0 mL of a 0.200 M HCl solution?

1 mol HCl = 36.5 g HCl ; 1 liter = 1000 mL

a. 60.0 x 0.200

b. 0.060 x 0.200

c. 60.0 / 0.200

d. 36.5 x 0.060 x 0.200

10.

What is the molarity of a solution made by dissolving 1.25 mol of HCl in enough water to make 625 mL of solution?

1 mol HCl = 36.5 g HCl ; 1 liter = 1000 mL

a. 1.25 x 0.625 x 36.5

b. 1.25 x 36.5 / 625

c. 625 /1.25

d. 1.25 / 0.625

11.

A 50.0 mL sample of 12.0 M HCl is diluted to 200 mL. What is true about the diluted solution?

1 mol HCl = 36.5 g HCl ; 1 liter = 1000 mL

a. the number of mols of solute stays the same

b. the concentration of the solution goes down to less than 6.0 M

c. the number of grams of dissolved solute stays the same

d. all of these

12.

Which of the following is the most concentrated solution?

a. a mixture of 300 mL of water and 20 grams NaOH

b. a mixture of 2000 mL of water and 2 mols of HCl

c. a mixture that gives 2000 mL of solution containing 4 mols of NH₃

d. a mixture that gives a solution of 1000 mL containing 4 mols of NH₃

13.

Which of the following describes a strong electrolyte?

a. a substance like NaCl that does not dissociate to give ions

b. a substance like CH3CH2CH2CH2CH2CH3 that does not dissociate to give ions

c. a substance like NaCl that dissociates completely to give ions

d. a substance that dissociates somewhat to give some ions

14.

Which of the following molecules is the most polar and most soluble in water?

a. hydrogen chloride, HCl

b. hydrogen iodide, HI

c. hydrogen, H₂

d. chlorine, Cl₂

15.

Which of the following produces exactly three ions from every formula unit when it dissolves?

a. sodium hydroxide, NaOH

b. Sodium bicarbonate, NaHCO₃

c. calcium chloride, CaCl₂

d. aluminum hydroxide, Al(OH)₃

1.	Explain why water is such a good solvent for polar compounds and ionic compounds.

1.	A solution of electrolytes will conduct electricity.
	a. true
	b. false

2.	Which of the following is the most concentrated solution?
	a. a mixture of 4000 mL of water and 2 mols NaOH
	b. a mixture of 2000 mL of water and 2 mols of HCl
	c. a mixture that gives 2000 mL of solution containing 4 mols of NH₃
	d. a mixture that gives a solution of 2000 mL containing 6 mols of NH₃

3.	Henry's law predicts which of the following?
	a. the concentration of dissolved acid in a solution
	b. the concentration of dissolved gas in a solution
	c. the concentration of dissolved base in a solution
	d. the concentration of acid needed to neutralize a base

4.	Water is the solute in which of the following mixtures?
	a. 100 mL of water and 20 grams of NaCl
	b. 100 mL of water and 200 mL of ethanol
	c. 1000 mL of water and 3 mols of NaOH
	d. 2 liters of aqueous solution containing 40 grams of NaOH

5.	The amount of dissolved gas in a solution will generally .......
	a. increase when the pressure of the gas decreases
	b. decrease when the pressure of the gas decreases
	c. decrease when the temperature of the solution decreases
	d. not change with pressure

6.	Which of the following is a nonelectrolyte?
	a. NaCl
	b. HCl
	c. NaHCO₃
	d. CH₃OH

7.	How many mols of CaCl₂ are dissolved in 250 mL of a 0.30 M CaCl₂ solution? 1 mol CaCl₂ = 111 g CaCl₂
	a. (0.250)(0.30)
	b. (0.250) / (0.30)
	c. (0.30) / (0.250)
	d. (0.250) x (111) / 0.30

8.	Which of the following statements is not true?
	a. all solutions are colorless
	b. suspensions are not transparent
	c. all the particles in a solution are atomic or molecular in size
	d. all solutions are homogeneous

9.	How many mols of HCl are dissolved in 60.0 mL of a 0.200 M HCl solution? 1 mol HCl = 36.5 g HCl ; 1 liter = 1000 mL
	a. 60.0 x 0.200
	b. 0.060 x 0.200
	c. 60.0 / 0.200
	d. 36.5 x 0.060 x 0.200

10.	What is the molarity of a solution made by dissolving 1.25 mol of HCl in enough water to make 625 mL of solution? 1 mol HCl = 36.5 g HCl ; 1 liter = 1000 mL
	a. 1.25 x 0.625 x 36.5
	b. 1.25 x 36.5 / 625
	c. 625 /1.25
	d. 1.25 / 0.625

11.	A 50.0 mL sample of 12.0 M HCl is diluted to 200 mL. What is true about the diluted solution? 1 mol HCl = 36.5 g HCl ; 1 liter = 1000 mL
	a. the number of mols of solute stays the same
	b. the concentration of the solution goes down to less than 6.0 M
	c. the number of grams of dissolved solute stays the same
	d. all of these

12.	Which of the following is the most concentrated solution?
	a. a mixture of 300 mL of water and 20 grams NaOH
	b. a mixture of 2000 mL of water and 2 mols of HCl
	c. a mixture that gives 2000 mL of solution containing 4 mols of NH₃
	d. a mixture that gives a solution of 1000 mL containing 4 mols of NH₃

13.	Which of the following describes a strong electrolyte?
	a. a substance like NaCl that does not dissociate to give ions
	b. a substance like CH3CH2CH2CH2CH2CH3 that does not dissociate to give ions
	c. a substance like NaCl that dissociates completely to give ions
	d. a substance that dissociates somewhat to give some ions

14.	Which of the following molecules is the most polar and most soluble in water?
	a. hydrogen chloride, HCl
	b. hydrogen iodide, HI
	c. hydrogen, H₂
	d. chlorine, Cl₂

15.	Which of the following produces exactly three ions from every formula unit when it dissolves?
	a. sodium hydroxide, NaOH
	b. Sodium bicarbonate, NaHCO₃
	c. calcium chloride, CaCl₂
	d. aluminum hydroxide, Al(OH)₃