Q: A solution is prepared by dissolving 2.355 g of H\_2SO\_4 (molar mass = 98.1 g/mol) in water and diluting to a final volume of 50.0 mL. What is the molarity of the solution?

$$M = \frac{2.355\,\text{g}}{98.1\,\text{g/mol} \times 0.0500\,\text{L}} = 0.481\,\text{M}$$

Q: A saline solution contains 1.5% (m/v) NaCl. How many grams of NaCl are needed to prepare 250 mL of this solution?

$$\text{Mass} = \frac{1.5\,\text{g}}{100\,\text{mL}} \times 250\,\text{mL} = 3.75\,\text{g}$$

Q: A 5.0% (m/v) glucose solution is commonly used intravenously. What is the osmolarity of this solution? (Molar mass of glucose = 180 g/mol)

$$\text{Osmolarity} = \frac{50\,\text{g}}{180\,\text{g/mol}} = 0.28\,\text{osmol/L}$$

Q: A solution is prepared by diluting 75 mL of a 3.5 M glucose solution to a final volume of 450 mL. What is the final concentration?

$$M_2$$ = \frac{$$M_1$$ $$V_1$$}{$$V_2$$} = \frac{3.5 \times 75}{450} = 0.58\,\text{M}$$

Question 1

Which of the following best describes a colloid?

Accepted Answer

A homogeneous mixture with particles ranging from 2 to 500 nm in diameter.

Question 2

A sample of seawater is classified as which type of mixture?

Accepted Answer

A homogeneous solution

Question 3

Which statement best explains why oil and water do not mix?

Accepted Answer

Oil is nonpolar and water is polar, so their intermolecular forces are too dissimilar.

Question 4

Which of the following pairs of substances would you expect to form a solution?

Accepted Answer

Carbon tetrachloride (CCl\_4) and hexane (C\_6H\_14)

Question 5

A solution is prepared by dissolving 2.355 g of H\_2SO\_4 (molar mass = 98.1 g/mol) in water and diluting to a final volume of 50.0 mL. What is the molarity of the solution?

Accepted Answer

$$M = \frac{2.355\,	ext{g}}{98.1\,	ext{g/mol} 	imes 0.0500\,	ext{L}} = 0.481\,	ext{M}$$

Question 6

Which of the following statements about solubility is correct?

Accepted Answer

Most solids become more soluble as temperature increases.

Question 7

A saline solution contains 1.5% (m/v) NaCl. How many grams of NaCl are needed to prepare 250 mL of this solution?

Accepted Answer

$$	ext{Mass} = \frac{1.5\,	ext{g}}{100\,	ext{mL}} 	imes 250\,	ext{mL} = 3.75\,	ext{g}$$

Question 8

According to Henry's Law, what happens to the solubility of a gas in a liquid if the partial pressure of the gas is doubled (at constant temperature)?

Accepted Answer

The solubility of the gas also doubles.

Question 9

A 5.0% (m/v) glucose solution is commonly used intravenously. What is the osmolarity of this solution? (Molar mass of glucose = 180 g/mol)

Accepted Answer

$$	ext{Osmolarity} = \frac{50\,	ext{g}}{180\,	ext{g/mol}} = 0.28\,	ext{osmol/L}$$

Question 10

Which of the following is a colligative property of solutions?

Accepted Answer

Boiling point elevation

Question 11

A solution is prepared by diluting 75 mL of a 3.5 M glucose solution to a final volume of 450 mL. What is the final concentration?

Accepted Answer

$$M_2$$ = \frac{$$M_1$$ $$V_1$$}{$$V_2$$} = \frac{3.5 	imes 75}{450} = 0.58\,	ext{M}$$

Question 12

Which of the following best describes a strong electrolyte?

Accepted Answer

A substance that ionizes completely in water.

Question 13

What is the boiling point of a solution containing 0.75 mol of KBr in 1.0 kg of water? (Assume KBr is a strong electrolyte and normal boiling point of water is 100°C)

Accepted Answer

$$	ext{Boiling point} = 100 + 0.51 	imes 1.5 = 100.77^\circ	ext{C}$$

Question 14

A tomato cell freezes at -2.5°C. What is the concentration of dissolved particles in the cell (in moles per kg of water)? (Freezing point depression constant for water = 1.86°C/mol)

Accepted Answer

$$	ext{Concentration} = \frac{2.5}{1.86} = 1.34\,	ext{mol/kg}$$

Question 15

Which of the following best describes osmosis?

Accepted Answer

The movement of solvent molecules through a semipermeable membrane from a region of lower solute concentration to higher solute concentration.

Question 16

A dialysis membrane allows which of the following to pass through?

Accepted Answer

Solvent molecules and small solute particles

Question 17

Which of the following medical scenarios best illustrates the concept of isotonic solutions?

Accepted Answer

Administering intravenous fluids with the same osmolarity as blood plasma to prevent cell shrinkage or swelling.

Chapter 9: Solutions – Fundamentals of General, Organic, and Biological Chemistry

Guida di studio - Domande di pratica

Study guide - Flashcard