Q: A reaction has a theoretical yield of 10.0 g and an actual yield of 8.5 g. What is the percent yield?

$$ \frac{8.5}{10.0} \times 100 = 85\% $$

Question 1

Which of the following best describes a chemical change?

Accepted Answer

Iron rusting when exposed to air.

Question 2

A student mixes aqueous solutions of silver nitrate and potassium chloride. What is the formula of the precipitate formed?

Accepted Answer

AgCl

Question 3

Which of the following is an example of an intensive property?

Accepted Answer

The density of mercury.

Question 4

Calculate the number of significant figures in the result of the following operation: $$ (0.523)(1.2161 - 0.99) + \left( \frac{2.648}{0.87} \right)(84 - 81.98) $$

Accepted Answer

1

Question 5

A 2.50 g sample of a compound contains 1.00 g of carbon, 0.33 g of hydrogen, and 1.17 g of oxygen. What is the empirical formula of the compound?

Accepted Answer

CH2O

Question 6

Which of the following statements about weak acids is NOT correct?

Accepted Answer

A weak acid has a very low concentration.

Question 7

A solution is prepared by dissolving 5.85 g of NaCl (molar mass = 58.44 g/mol) in enough water to make 0.500 L of solution. What is the molarity of the solution?

Accepted Answer

0.100 M

Question 8

Which of the following is a pure substance?

Accepted Answer

Sucrose (table sugar)

Question 9

A reaction has a theoretical yield of 10.0 g and an actual yield of 8.5 g. What is the percent yield?

Accepted Answer

$$ \frac{8.5}{10.0} 	imes 100 = 85\% $$

Question 10

Which of the following best describes the role of a limiting reactant in a chemical reaction?

Accepted Answer

It determines the maximum amount of product that can be formed.

Question 11

Which of the following compounds is insoluble in water?

Accepted Answer

BaSO4

Question 12

A student needs to prepare 250.0 mL of a 0.100 M NaCl solution. How many grams of NaCl (molar mass = 58.44 g/mol) are required?

Accepted Answer

1.46 g

Question 13

Which of the following is the correct net ionic equation for the reaction between hydrochloric acid and sodium hydroxide?

Accepted Answer

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

Question 14

A 10.0 g sample of calcium carbonate decomposes according to the equation $$ \mathrm{$$CaCO_3$$ (s) \rightarrow CaO (s) + CO_2$ (g)} . $$What mass of CO2 is produced?

Accepted Answer

4.40 g

Question 15

Which of the following is a chemical property of hydrogen gas?

Accepted Answer

It reacts explosively with oxygen.

Question 16

A sample of gas occupies 22.4 L at STP. How many moles of gas are present?

Accepted Answer

1.00 mol

Question 17

Which of the following best describes a solution?

Accepted Answer

A homogeneous mixture of two or more substances.

Question 18

Which of the following is the correct balanced equation for the reaction of aluminum with chlorine gas to form aluminum chloride?

Accepted Answer

$$ 2 \mathrm{Al (s) + 3 Cl_2$ (g) \rightarrow 2 $$AlCl_3$$ (s)} $$

Question 19

A 5.00 g sample of magnesium reacts with excess hydrochloric acid to produce hydrogen gas. How many liters of hydrogen gas are produced at STP? $$ \mathrm{Mg (s) + 2 HCl (aq) \rightarrow $$MgCl_2$$ (aq) + H_2$ (g)} $$

Accepted Answer

2.06 L

General Chemistry I: Key Concepts, Calculations, and Exam Review

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