$$M = \frac{0.5}{0.5} = 1.0\ \text{M}$$

$$M = \frac{25\ \text{g}}{119.0\ \text{g/mol}} = 0.21\ \text{mol};\ M = \frac{0.21}{0.5} = 0.42\ \text{M}$$

$$0.35\ \text{mol/L} \times 0.450\ \text{L} = 0.158\ \text{mol};\ 0.158\ \text{mol} \times 58.44\ \text{g/mol} = 9.2\ \text{g}$$

$$\text{Pb}^{2+}(aq) + 2\text{Cl}^-(aq) \rightarrow \text{PbCl}_2(s)$$

Question 1

Which of the following best describes a strong electrolyte in aqueous solution?

Accepted Answer

A substance that completely ionizes in water, producing only ions.

Question 2

A solution is prepared by dissolving 5 g of NaOH in 50 g of H$$_2O. $$Which is the solute and which is the solvent?

Accepted Answer

NaOH is the solute, H$$_2O is $$the solvent.

Question 3

What is the definition of molarity ($$M$$)?

Accepted Answer

The number of moles of solute per liter of solution: $$M = \frac{	ext{moles of solute}}{	ext{L of solution}}$$

Question 4

What is the molarity of a solution containing 0.5 moles of KCl in 0.5 L of solution?

Accepted Answer

$$M = \frac{0.5}{0.5} = 1.0\ 	ext{M}$$

Question 5

What is the molarity of a solution which contains 25 g of potassium bromide (KBr, molar mass = 119.0 g/mol) dissolved in 0.500 L of solution?

Accepted Answer

$$M = \frac{25\ 	ext{g}}{119.0\ 	ext{g/mol}} = 0.21\ 	ext{mol};\ M = \frac{0.21}{0.5} = 0.42\ 	ext{M}$$

Question 6

How many grams of NaCl are present in 450 mL of a 0.35 M NaCl solution? (Molar mass NaCl = 58.44 g/mol)

Accepted Answer

$$0.35\ 	ext{mol/L} 	imes 0.450\ 	ext{L} = 0.158\ 	ext{mol};\ 0.158\ 	ext{mol} 	imes 58.44\ 	ext{g/mol} = 9.2\ 	ext{g}$$

Question 7

During the process of diluting a solution to a lower concentration, which of the following statements is correct?

Accepted Answer

The amount of solute remains the same, the volume increases, and the concentration decreases.

Question 8

What is the final molarity when 80.0 mL of a 0.400 M NaCl solution is diluted to a final volume of 240.0 mL?

Accepted Answer

$$M_1V_1 = M_2V_2;\ (0.400)(80.0) = M_2$(240.0);\ M_2$ = \frac{32}{240} = 0.133\ 	ext{M}$$

Question 9

Which of the following is the balanced net ionic equation for the reaction between Pb(NO$$_3$$)$$_2$$ and KCl in aqueous solution?

Accepted Answer

$$	ext{Pb}^{2+}(aq) + 2	ext{Cl}^-(aq) ightarrow 	ext{PbCl}_2(s)$$

Question 10

Which ions are spectator ions in the reaction between Pb(NO$$_3$$)$$_2$$ and KCl?

Accepted Answer

K$$^+$$ and NO$$_3^-$$

Question 11

Which of the following best describes oxidation and reduction?

Accepted Answer

Oxidation is the loss of electrons; reduction is the gain of electrons.

Question 12

In the reaction $$	ext{Mg}(s) + 2	ext{HCl}(aq) ightarrow 	ext{MgCl}_2(aq) + 	ext{H}_2(g)$$, which substance is reduced?

Accepted Answer

H$$^+ ($$from HCl)

Question 13

Which of the following is a strong base?

Accepted Answer

NaOH

Question 14

What is the mass percent concentration of a solution containing 10 g of NaCl dissolved in 90 g of water?

Accepted Answer

$$	ext{Mass percent} = \frac{10}{10+90} 	imes 100\% = 10\%$$

Question 15

Which of the following compounds will produce a precipitate when mixed in aqueous solution?

Accepted Answer

Pb(NO$$_3$$)$$_2 (aq) $$and HCl (aq)

Question 16

Which of the following best explains why oil does not dissolve in water, but methanol does?

Accepted Answer

Oil is nonpolar and does not form hydrogen bonds with water, while methanol is polar and forms hydrogen bonds with water.

Question 17

What is the molarity of a solution containing 60 g of NaCl dissolved in 350 mL of solution? (Molar mass NaCl = 58.44 g/mol)

Accepted Answer

$$M = \frac{60}{58.44} = 1.027\ 	ext{mol};\ M = \frac{1.027}{0.350} = 2.94\ 	ext{M}$$

Solutions, Electrolytes, and Chemical Reactions: Analytical Chemistry Study Guide

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