Q: A patient’s blood test shows a calcium ion concentration of 8.8 mEq/L. How many moles of $$Ca^{2+}$$ are present in 0.50 L of blood? (1 Eq = 1 mol of charge)

$$\frac{8.8 \times 0.50}{2 \times 1000} = 0.0022$$ mol

Q: A 0.50 L sample of 6.0 M HCl is diluted to a final volume of 1.0 L. What is the final concentration?

$$C_1V_1 = C_2V_2$$; $$6.0 \times 0.50 = C_2$ \times 1.0$$; $$C_2 = 3.0$ M

Q: A solution is prepared by mixing 15.0 g of Na_2CO_3 and 235 g of H_2O. What is the mass percent (m/m) of Na_2CO_3 in the solution?

$$\frac{15.0}{15.0 + 235} \times 100 = 6.0\%$$

Question 1

Which of the following statements best explains why NaCl dissolves readily in water?

Accepted Answer

NaCl is an ionic compound and water is a polar solvent, allowing strong ion-dipole interactions to overcome the lattice energy of NaCl.

Question 2

A solution is prepared by dissolving 10.0 g of sugar in 100 mL of water. Which is the solute and which is the solvent?

Accepted Answer

Sugar is the solute; water is the solvent.

Question 3

Which of the following best describes a saturated solution?

Accepted Answer

A solution in which no more solute can dissolve and undissolved solute is present at the bottom.

Question 4

Which of the following compounds will NOT dissolve in water?

Accepted Answer

C_6H_{14} (hexane)

Question 5

Which of the following is a strong electrolyte in aqueous solution?

Accepted Answer

NaCl

Question 6

A patient’s blood test shows a calcium ion concentration of 8.8 mEq/L. How many moles of $$Ca^{2+}$$ are present in 0.50 L of blood? (1 Eq = 1 mol of charge)

Accepted Answer

$$\frac{8.8 	imes 0.50}{2 	imes 1000} = 0.0022$$ mol

Question 7

Which of the following best describes the process of osmosis?

Accepted Answer

Solvent molecules move from low solute concentration to high solute concentration through a semipermeable membrane.

Question 8

A red blood cell is placed in a 2% NaCl solution. What will happen to the cell?

Accepted Answer

It will shrink (crenation).

Question 9

Which of the following equations correctly represents the dissociation of $$CaCl_2 in $$water?

Accepted Answer

$$\mathrm{$$CaCl_2$$(s) \rightarrow Ca$$^{2+}$$(aq) + 2Cl^-(aq)}$$

Question 10

What is the molarity of a solution prepared by dissolving 34.8 g of $$KNO_3 ($$molar mass = 101 g/mol) in enough water to make 0.225 L of solution?

Accepted Answer

$$\frac{34.8}{101} = 0.344$$ mol; $$\frac{0.344}{0.225} = 1.53 M$$

Question 11

A 0.50 L sample of 6.0 M HCl is diluted to a final volume of 1.0 L. What is the final concentration?

Accepted Answer

$$C_1V_1 = C_2V_2$$; $$6.0 	imes 0.50 = C_2$ 	imes 1.0$$; $$C_2 = 3.0$ M

Question 12

Which of the following best describes a colloid?

Accepted Answer

A mixture with medium-sized particles that do not settle out and cannot be separated by filtration but can be separated by semipermeable membranes.

Question 13

Which of the following solutions is isotonic to red blood cells?

Accepted Answer

0.9% (m/v) NaCl

Question 14

A solution is prepared by mixing 15.0 g of Na_2CO_3 and 235 g of H_2O. What is the mass percent (m/m) of Na_2CO_3 in the solution?

Accepted Answer

$$\frac{15.0}{15.0 + 235} 	imes 100 = 6.0\%$$

Question 15

Which of the following best explains why a bottle of carbonated drink may burst when left in the hot sun?

Accepted Answer

The solubility of gases in liquids decreases as temperature increases, causing excess $$CO_2 to $$escape and increase pressure.

Question 16

Which of the following is the correct formula for calculating molarity?

Accepted Answer

$$M = \frac{	ext{moles of solute}}{	ext{liters of solution}}$$

Question 17

A solution is prepared by diluting 10.0 mL of 9.00% NaOH to 60.0 mL. What is the final percent (m/v) of NaOH?

Accepted Answer

$$C_1V_1 = C_2V_2$$; $$9.00 	imes 10.0 = C_2$ 	imes 60.0$$; $$C_2 = 1.5$$\%$$

Question 18

Which of the following best describes the effect of increasing pressure on the solubility of a gas in a liquid?

Accepted Answer

The solubility of the gas increases as pressure increases.

Solutions: Properties, Types, and Examples (General Chemistry Chapter 9 Study Notes)

Guida di studio - Domande di pratica

Study guide - Flashcard