Question 1

Gallium has an atomic mass of 69.723 u. The abundance of $$^{69}\mathrm{Ga} (68.926 u) is 60.11$$%. What is the atomic mass, in u, of the other isotope of gallium?

Accepted Answer

$$^{71}\mathrm{Ga} = 70.924$$\ \mathrm{u}$

Question 2

What is the correct IUPAC name for $$\mathrm{Ba(NO_3$)_2}$$?

Accepted Answer

Barium nitrate

Question 3

Which of the following is the correct chemical formula for disulfur tetrafluoride?

Accepted Answer

$$\mathrm{S_2F_4}$$

Question 4

Which of the following is the correct structure for 3,3-dimethylpent-1-yne?

Accepted Answer

A five-carbon chain with a triple bond between C1 and C2, and two methyl groups attached to C3

Question 5

What is the correct name for the following ion: $$\mathrm{CH_3CH_2O^-}$$?

Accepted Answer

Ethoxide ion

Question 6

Consider the combustion reaction: $$\mathrm{C_7H_{16} + O_2$ \rightarrow CO_2$ + H_2O}. If 1.200 g of $$heptane ($$\mathrm{C_7H_{16}}) $$produces 2.086 g of $$\mathrm{CO_2$}$$ and 1.134 g of $$\mathrm{H_2O}$$, what is the empirical formula of the hydrocarbon?

Accepted Answer

$$\mathrm{C_7H_{16}}$$

Question 7

Balance the following redox reaction in acidic solution: $$\mathrm{SO_3$^{2-} (aq) + $$MnO_4$$^- (aq) \rightarrow SO_4$^{2-} (aq) + Mn$$^{2+}$$ (aq)}$$

Accepted Answer

$$5\mathrm{SO_3$^{2-}} + 2\mathrm{$$MnO_4$$^-} + 6\mathrm{H^+} \rightarrow 5\mathrm{SO_4$^{2-}} + 2\mathrm{Mn$$^{2+}$$} + 3\mathrm{H_2O}$$

Question 8

Lead ions can be precipitated from solution with KCl according to the following reaction: $$\mathrm{Pb$$^{2+}$$ (aq) + 2KCl (aq) \rightarrow $$PbCl_2$$ (s) + 2K^+ (aq)}. $$When 28.5 g KCl is added to a solution containing 7.5 g $$\mathrm{Pb$$^{2+}$$}$$, what is the mass of $$\mathrm{$$PbCl_2$$}$$ precipitate formed? (Molar masses: KCl = 74.55 g/mol, Pb$$^{2+} = 207.2 g/$$mol, PbCl$$_2 = 278.1 g/$$mol)

Accepted Answer

29.2 g

Question 9

A gas occupies 3.33 L at 2.23 bar. What is the volume at 2.50 bar if the temperature and number of moles remain constant?

Accepted Answer

2.97 L

Question 10

A total of 0.35 g of Ar(g) are contained in a 300 mL vessel at a pressure of 1.3 bar. Calculate the temperature of the gas. (Molar mass of Ar = 39.95 g/mol, $$R = 0.08314\ \mathrm{L \cdot bar \cdot K$$^{-1}$$ \cdot $$mol^{-1}$$})$$

Accepted Answer

41.7 K

Question 11

Which of the following best describes a redox reaction?

Accepted Answer

A reaction in which electrons are transferred from one species to another

Question 12

Which of the following is a correct net ionic equation for the precipitation of lead(II) chloride from aqueous solutions of lead(II) nitrate and potassium chloride?

Accepted Answer

$$\mathrm{Pb$$^{2+}$$ (aq) + 2Cl^- (aq) \rightarrow $$PbCl_2$$ (s)}$$

Question 13

Which of the following statements about empirical and molecular formulas is correct?

Accepted Answer

The empirical formula is the simplest whole-number ratio of atoms in a compound, while the molecular formula gives the actual number of atoms of each element in a molecule.

Question 14

Which of the following best explains why gases are compressible while solids are not?

Accepted Answer

Gas particles are far apart with negligible intermolecular forces, allowing them to be compressed.

Question 15

A sample of gas is transferred from a 2.00 L container at 1.00 bar to a 4.00 L container at constant temperature. What is the final pressure?

Accepted Answer

0.50 bar

Question 16

Which of the following is the correct name for $$\mathrm{SO_2$}$$?

Accepted Answer

Sulfur dioxide

Question 17

Which of the following is a correct balanced equation for the combustion of methane ($$\mathrm{CH_4$}$$)?

Accepted Answer

$$\mathrm{CH_4$ + 2O_2 \rightarrow CO_2$ + 2H_2O}$$

General Chemistry Practice Questions: Atomic Mass, Nomenclature, Stoichiometry, and Gas Laws

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