Q: What is the molarity of a solution prepared by dissolving 29.2 g of KBr (molar mass = 119.0 g/mol) in enough water to make 500.0 mL of solution?

$$M = \frac{29.2\ \text{g}}{119.0\ \text{g/mol}} \div 0.500\ \text{L} = 0.491\ \text{M}$$

Q: A laboratory technician needs to prepare 250.0 mL of a 1.50 M KBr solution. What mass of KBr should be used?

$$\text{mass} = 1.50\ \text{mol/L} \times 0.250\ \text{L} \times 119.0\ \text{g/mol} = 44.6\ \text{g}$$

Q: How many milliliters of a 0.155 M KCl solution contain 2.55 g of KCl (molar mass = 74.55 g/mol)?

$$\text{mL} = \frac{2.55\ \text{g}}{74.55\ \text{g/mol}} \div 0.155\ \text{mol/L} \times 1000 = 220\ \text{mL}$$

Q: What is the net ionic equation for the reaction between aqueous solutions of AgNO3 and NaCl?

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

Q: A titration requires 12.54 mL of 0.100 M NaOH to neutralize 10.00 mL of HCl solution. What is the concentration of the HCl solution?

$$M_{\text{HCl}} = \frac{0.100\ \text{mol/L} \times 0.01254\ \text{L}}{0.01000\ \text{L}} = 0.125\ \text{M}$$

Q: Which of the following is a redox reaction?

$$2\ \text{Na}(s) + \text{Cl}_2(g) \rightarrow 2\ \text{NaCl}(s)$$

Q: Which of the following reactions is a precipitation reaction?

$$2\ \text{KI}(aq) + \text{Pb(NO}_3)_2(aq) \rightarrow 2\ \text{KNO}_3(aq) + \text{PbI}_2(s)$$

Question 1

Which of the following best describes a solution in chemistry?

Accepted Answer

A homogeneous mixture in which the solute is evenly distributed within the solvent.

Question 2

What is the molarity of a solution prepared by dissolving 29.2 g of KBr (molar mass = 119.0 g/mol) in enough water to make 500.0 mL of solution?

Accepted Answer

$$M = \frac{29.2\ 	ext{g}}{119.0\ 	ext{g/mol}} \div 0.500\ 	ext{L} = 0.491\ 	ext{M}$$

Question 3

A laboratory technician needs to prepare 250.0 mL of a 1.50 M KBr solution. What mass of KBr should be used?

Accepted Answer

$$	ext{mass} = 1.50\ 	ext{mol/L} 	imes 0.250\ 	ext{L} 	imes 119.0\ 	ext{g/mol} = 44.6\ 	ext{g}$$

Question 4

Which equation correctly relates the concentrations and volumes before and after dilution?

Accepted Answer

$$M_1V_1 = M_2V_2$$

Question 5

How many milliliters of a 0.155 M KCl solution contain 2.55 g of KCl (molar mass = 74.55 g/mol)?

Accepted Answer

$$	ext{mL} = \frac{2.55\ 	ext{g}}{74.55\ 	ext{g/mol}} \div 0.155\ 	ext{mol/L} 	imes 1000 = 220\ 	ext{mL}$$

Question 6

Which of the following statements about electrolytes is TRUE?

Accepted Answer

A strong electrolyte completely dissociates into ions in water.

Question 7

Which of the following compounds will form a precipitate when mixed with an aqueous solution of Na2CO3?

Accepted Answer

Ba(NO3)2

Question 8

What is the net ionic equation for the reaction between aqueous solutions of AgNO3 and NaCl?

Accepted Answer

$$	ext{Ag}^+(aq) + 	ext{Cl}^-(aq) ightarrow 	ext{AgCl}(s)$$

Question 9

Which of the following acids is correctly named?

Accepted Answer

H2SO4: sulfuric acid

Question 10

A titration requires 12.54 mL of 0.100 M NaOH to neutralize 10.00 mL of HCl solution. What is the concentration of the HCl solution?

Accepted Answer

$$M_{	ext{HCl}} = \frac{0.100\ 	ext{mol/L} 	imes 0.01254\ 	ext{L}}{0.01000\ 	ext{L}} = 0.125\ 	ext{M}$$

Question 11

Which of the following is a redox reaction?

Accepted Answer

$$2\ 	ext{Na}(s) + 	ext{Cl}_2(g) ightarrow 2\ 	ext{NaCl}(s)$$

Question 12

Assign the oxidation state to sulfur in $$SO_4$$^{2-}$$.

Accepted Answer

$$+6$$

Question 13

Which of the following best describes the role of a reducing agent in a redox reaction?

Accepted Answer

It donates electrons and is oxidized.

Question 14

Which of the following reactions is a precipitation reaction?

Accepted Answer

$$2\ 	ext{KI}(aq) + 	ext{Pb(NO}_3)_2(aq) ightarrow 2\ 	ext{KNO}_3(aq) + 	ext{PbI}_2(s)$$

Question 15

Which of the following is the correct net ionic equation for the reaction of $$CO_3$$^{2-}(aq)$$ with H^+(aq$$)$$?

Accepted Answer

$$CO_3$$^{2-}(aq) + 2 H^+(aq) \rightarrow $$CO_2(g) + H_2O(l$$)$$

Question 16

Which of the following best explains why NaCl conducts electricity in water but sugar does not?

Accepted Answer

NaCl dissociates into ions, while sugar dissolves as molecules.

Question 17

Which of the following is the correct complete ionic equation for the reaction: $$2\ $$AgNO_3$$(aq) + $$MgCl_2$$(aq) \rightarrow 2\ AgCl(s) + Mg(NO_3$)_2(aq)$$?

Accepted Answer

$$2\ Ag^+(aq) + 2\ NO_3$^-(aq) + Mg$$^{2+}$$(aq) + 2\ Cl^-(aq) \rightarrow 2\ AgCl(s) + Mg$$^{2+}$$(aq) + 2\ NO_3$^-(aq)$$

Chapter 8: Introduction to Solutions and Aqueous Reactions – Comprehensive Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard