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

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

Question 2

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

Accepted Answer

Barium nitrate

Question 3

What is the 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: $$\mathrm{CH_3CH_2CH_2O^-}$$?

Accepted Answer

Propoxide ion

Question 6

Consider the combustion reaction: $$\mathrm{C_7H_{16} + O_2$ \rightarrow CO_2$ + H_2O}. If 1.200 g of $$heptane ($$\mathrm{C_7H_{16}}) is $$combusted and 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

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

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

29.4 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, $$R = 0.08314 L$$·bar·K$$^{-1}$$·mol$$^{-1})$$

Accepted Answer

43 K

Question 11

Which of the following best describes a combustion reaction?

Accepted Answer

A reaction in which a substance reacts with oxygen to produce heat and light, typically forming $$\mathrm{CO_2$}$$ and $$\mathrm{H_2O}$$

Question 12

Which of the following is the correct net ionic equation for the precipitation of lead(II) chloride from 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 gives 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

A sample of a hydrocarbon is combusted and produces only $$\mathrm{CO_2$}$$ and $$\mathrm{H_2O}. $$Which of the following best explains how to determine the empirical formula of the hydrocarbon?

Accepted Answer

Calculate the moles of C and H from the masses of $$\mathrm{CO_2$}$$ and $$\mathrm{H_2O}$$ produced, then find the simplest whole-number ratio.

Question 15

Which of the following is a correct application of the ideal gas law?

Accepted Answer

Calculating the number of moles of a gas when pressure, volume, and temperature are known: $$n = \frac{PV}{RT}$$

Question 16

Which of the following best describes a redox reaction?

Accepted Answer

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

Question 17

Which of the following is the correct balanced equation for the combustion of octane ($$\mathrm{C_8H_{18}}$$)?

Accepted Answer

$$\mathrm{2C_8H_{18} + 25O_2 \rightarrow 16CO_2 + 18H_2O}$$

General Chemistry Practice Questions: Atomic Structure, Nomenclature, Chemical Equations, and Gas Laws

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