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{$$M_1$$ $$V_1$$}{$$M_2$$} = \frac{5.0 \times 100}{0.54} = 926\ \mathrm{mL}$$

Q: How many moles of Ca$$^{2+}$$ ions are in 0.120 L of 0.450 M Ca$$_3(PO$_4$$)$$_2$$ solution?

$$0.120 \times 0.450 \times 3 = 0.162\ \mathrm{mol}$$

Q: A solution is prepared by dissolving 2.81 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?

$$\frac{2.81}{0.075 \times 0.150} = 250\ \mathrm{g/mol}$$

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 form 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

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

Question 4

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

Accepted Answer

0.10 M AlBr3

Question 5

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{$$M_1$$ $$V_1$$}{$$M_2$$} = \frac{5.0 	imes 100}{0.54} = 926\ \mathrm{mL}$$

Question 6

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

Accepted Answer

BaSO4

Question 7

Which of the following represents a strong electrolyte?

Accepted Answer

CsH

Question 8

Which of the following represents a non-electrolyte?

Accepted Answer

C2H5OH

Question 9

Which of the following is a precipitation reaction?

Accepted Answer

ZnBr2 (aq) + 2 KOH (aq) → Zn(OH)2 (s) + 2 KBr (aq)

Question 10

How many moles of Ca$$^{2+}$$ ions are in 0.120 L of 0.450 M Ca$$_3(PO$_4$$)$$_2$$ solution?

Accepted Answer

$$0.120 	imes 0.450 	imes 3 = 0.162\ \mathrm{mol}$$

Question 11

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

Accepted Answer

O2

Question 12

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

Chromium

Question 13

Which of the following reactions is a redox reaction?

Accepted Answer

I, II, III, and IV

Question 14

A solution is prepared by dissolving 2.81 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

$$\frac{2.81}{0.075 	imes 0.150} = 250\ \mathrm{g/mol}$$

Question 15

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

Accepted Answer

It gains electrons and is reduced.

Question 16

Which of the following pairs of compounds is insoluble in water?

Accepted Answer

PbSO4 and Pb3(PO4)2

Question 17

Which of the following statements is true?

Accepted Answer

Zinc bromide, ZnBr2, represents a strong electrolyte.

Question 18

Which of the following best describes the process of dilution?

Accepted Answer

Adding more solvent to a solution to decrease its concentration.

Question 19

Which of the following is the correct net ionic equation for the reaction between aqueous solutions of copper(II) bromide and lithium hydroxide?

Accepted Answer

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

Reactions in Aqueous Solution: Solutions, Molarity, Solubility, Electrolytes, and Redox Reactions

Guida di studio - Domande di pratica

Study guide - Flashcard