Q: A student dissolves 35.2 g of NaCl in enough water to make 500 mL of solution. What is the molarity of the solution? (Molar mass of NaCl = 58.44 g/mol)

$$\mathrm{M = \frac{35.2\ g}{58.44\ g/mol \times 0.500\ L} = 1.21\ M}$$

Q: A 400 mL sample of 1.0 M KMnO4 is diluted to a final volume of 1.0 L. What is the final molarity of the solution?

$$\mathrm{M_2$ = \frac{M_1$ V_1$}{V_2$} = \frac{1.0\ M \times 0.400\ L}{1.0\ L} = 0.40\ M}$$

Q: A 200 mL solution of 0.866 M NaOH is prepared from a 5.07 M stock solution. What volume of stock solution is required?

$$\mathrm{V_1$ = \frac{M_2$ V_2$}{M_1$} = \frac{0.866\ M \times 0.200\ L}{5.07\ M} = 0.0342\ L = 34.2\ mL}$$

Question 1

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

Accepted Answer

It completely dissociates into ions in water, resulting in a solution that conducts electricity well.

Question 2

Which of the following compounds will form a precipitate when mixed with a solution of Na2SO4, according to the solubility rules?

Accepted Answer

BaCl2

Question 3

What is the net ionic equation for the reaction between AgNO3(aq) and NaCl(aq)?

Accepted Answer

$$\mathrm{Ag^+ (aq) + Cl^- (aq) \rightarrow AgCl (s)}$$

Question 4

A student dissolves 35.2 g of NaCl in enough water to make 500 mL of solution. What is the molarity of the solution? (Molar mass of NaCl = 58.44 g/mol)

Accepted Answer

$$\mathrm{M = \frac{35.2\ g}{58.44\ g/mol 	imes 0.500\ L} = 1.21\ M}$$

Question 5

Which of the following is a correct statement about spectator ions in a chemical reaction?

Accepted Answer

Spectator ions are unchanged and appear on both sides of the ionic equation.

Question 6

Which of the following acids is a weak electrolyte in aqueous solution?

Accepted Answer

CH3COOH

Question 7

A 400 mL sample of 1.0 M KMnO4 is diluted to a final volume of 1.0 L. What is the final molarity of the solution?

Accepted Answer

$$\mathrm{M_2$ = \frac{M_1$ V_1$}{V_2$} = \frac{1.0\ M 	imes 0.400\ L}{1.0\ L} = 0.40\ M}$$

Question 8

Which of the following reactions is a redox reaction?

Accepted Answer

$$\mathrm{Zn (s) + Cu$$^{2+}$$ (aq) \rightarrow Zn$$^{2+}$$ (aq) + Cu (s)}$$

Question 9

Assign oxidation numbers to all elements in PbO and CO, and identify which element is oxidized and which is reduced in the reaction: $$\mathrm{PbO + CO \rightarrow Pb + CO_2$}$$

Accepted Answer

Pb: +2 in PbO, 0 in Pb; C: +2 in CO, +4 in CO2. C is oxidized, Pb is reduced.

Question 10

Which of the following is a correct net ionic equation for the reaction between HCl(aq) and NaOH(aq)?

Accepted Answer

$$\mathrm{H^+ (aq) + OH^- (aq) \rightarrow H_2O (l)}$$

Question 11

A 200 mL solution of 0.866 M NaOH is prepared from a 5.07 M stock solution. What volume of stock solution is required?

Accepted Answer

$$\mathrm{V_1$ = \frac{M_2$ V_2$}{M_1$} = \frac{0.866\ M 	imes 0.200\ L}{5.07\ M} = 0.0342\ L = 34.2\ mL}$$

Question 12

Which of the following is a property of acids?

Accepted Answer

They react with carbonates to produce carbon dioxide gas.

Question 13

Which of the following compounds is insoluble in water according to the solubility rules?

Accepted Answer

CaCO3

Question 14

A sample of 0.322 g of an ionic compound containing Br- is dissolved in water and treated with excess AgNO3, forming 0.6964 g of AgBr. What is the percent by mass of Br in the original compound? (Molar mass of AgBr = 187.77 g/mol, Br = 79.90 g/mol)

Accepted Answer

$$\mathrm{\%Br = \frac{0.6964\ g}{187.77\ g/mol} 	imes 79.90\ g/mol \div 0.322\ g 	imes 100 = 86.2\%}$$

Question 15

Which of the following is a Bronsted-Lowry acid?

Accepted Answer

HCl

Question 16

Which of the following reactions is a decomposition reaction?

Accepted Answer

$$\mathrm{2KClO_3 \rightarrow 2KCl + 3O_2}$$

Question 17

Which of the following metals will displace hydrogen from cold water?

Accepted Answer

Na

Question 18

How many milliliters of 1.28 M H2SO4 are required to neutralize 60.2 mL of 0.427 M KOH? (Assume complete reaction: $$\mathrm{2KOH + H_2SO_4 \rightarrow K_2SO_4 + 2H_2O})$$

Accepted Answer

$$\mathrm{V_{H_2SO_4} = \frac{M_{KOH} V_{KOH}}{2 M_{H_2SO_4}} = \frac{0.427 	imes 60.2}{2 	imes 1.28} = 10.0\ mL}$$

Aqueous Solutions and Chemical Reactions: Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard