Q: Calculate the molarity of a solution prepared by dissolving 23.7 g NaOH (MW: 40.00 g/mol) in enough water to make 2.50 L of solution.

$$M = \frac{23.7}{40.00} \div 2.50 = 0.237\ \text{M}$$

Q: How many grams of $$\mathrm{Na_3PO_4} (MW$$: 163.94 g/mol) are present in 300.0 mL of a 0.550 M $$\mathrm{Na_3PO_4}$$ solution?

$$0.550 \times 0.300 \times 163.94 = 27.1\ \text{g}$$

Q: What is the final volume (in mL) when 100 mL of 5.0 M KCl is diluted to make a 0.54 M KCl solution?

$$V_2$$ = \frac{M_1V_1}{$$M_2$$} = \frac{5.0 \times 100}{0.54} = 926\ \text{mL}$$

Q: A solution is prepared by dissolving 2.64 g of an unknown compound in water to yield 150 mL of solution. The concentration is 0.075 M. What is the molecular weight of the substance?

$$\text{MW} = \frac{2.64}{0.075 \times 0.150} = 234.7\ \text{g/mol}$$

Question 1

Which of the following best describes a solution in chemistry?

Accepted Answer

A homogeneous mixture of two or more substances with uniform composition.

Question 2

A student dissolves 10.0 g of NaCl in 500.0 mL of water. Which statement is correct?

Accepted Answer

10.0 g NaCl is the solute, 500.0 mL of water is the solvent, and together they are a solution.

Question 3

Calculate the molarity of a solution prepared by dissolving 23.7 g NaOH (MW: 40.00 g/mol) in enough water to make 2.50 L of solution.

Accepted Answer

$$M = \frac{23.7}{40.00} \div 2.50 = 0.237\ 	ext{M}$$

Question 4

How many grams of $$\mathrm{Na_3PO_4} (MW$$: 163.94 g/mol) are present in 300.0 mL of a 0.550 M $$\mathrm{Na_3PO_4}$$ solution?

Accepted Answer

$$0.550 	imes 0.300 	imes 163.94 = 27.1\ 	ext{g}$$

Question 5

Which of the following solutions will have the highest concentration of bromide ions?

Accepted Answer

0.10 M AlBr3

Question 6

What is the final volume (in mL) when 100 mL of 5.0 M KCl is diluted to make a 0.54 M KCl solution?

Accepted Answer

$$V_2$$ = \frac{M_1V_1}{$$M_2$$} = \frac{5.0 	imes 100}{0.54} = 926\ 	ext{mL}$$

Question 7

According to solubility rules, which of the following ionic compounds will be insoluble in water?

Accepted Answer

BaSO4

Question 8

Which of the following represents a strong electrolyte?

Accepted Answer

NaOH

Question 9

Which of the following is a precipitation reaction?

Accepted Answer

ZnBr2 (aq) + 2 KOH (aq) $$\rightarrow Zn(OH)2 (s) + 2 $$KBr (aq)

Question 10

Which of the following compounds has oxygen with the lowest oxidation state?

Accepted Answer

O2

Question 11

Which element is being reduced in the following reaction? $$\mathrm{Cr_2O_7$$^{2-}$$ + 3 $$HNO_2$$ + 5 H^+ \rightarrow 2 Cr$$^{3+}$$ + 3 NO_3$^- + 4 H_2O}$$

Accepted Answer

Cr

Question 12

Which of the following reactions is a redox reaction?

Accepted Answer

2 AgNO3 (aq) + Cu (s) $$\rightarrow Cu(NO3)2 (aq) + 2 Ag (s)$$

Question 13

A solution is prepared by dissolving 2.64 g of an unknown compound in water to yield 150 mL of solution. The concentration is 0.075 M. What is the molecular weight of the substance?

Accepted Answer

$$	ext{MW} = \frac{2.64}{0.075 	imes 0.150} = 234.7\ 	ext{g/mol}$$

Question 14

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

Accepted Answer

It is the substance that gains electrons.

Question 15

Which of the following reagents could be used to separate the two cations from a solution containing Lead (IV) acetate and cesium permanganate?

Accepted Answer

K2S

Question 16

What is the correct net ionic equation for the reaction between aqueous copper(II) bromide and lithium hydroxide?

Accepted Answer

$$\mathrm{Cu$$^{2+}$$ (aq) + 2 OH^- (aq) \rightarrow Cu(OH)_2 (s)}$$

Question 17

Which of the following is true regarding strong electrolytes?

Accepted Answer

They completely dissociate into ions in solution.

Question 18

Which of the following best describes a colloid?

Accepted Answer

A heterogeneous mixture with intermediate-sized solute particles that do not settle out.

Ch. 8 - Introduction to Solutions and Aqueous Reactions: Comprehensive Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard