Q: Which of the following is the correct formula for calculating percent yield?

$$\frac{\text{actual yield}}{\text{theoretical yield}} \times 100\%$$

Question 1

Which of the following best describes the greenhouse effect as it relates to Earth's atmosphere?

Accepted Answer

Greenhouse gases allow sunlight to enter, warm Earth's surface, and trap some heat from escaping.

Question 2

Balance the following chemical equation for the combustion of methane: $$\mathrm{CH_4$(g) + O_2$(g) \rightarrow CO_2$(g) + H_2O(g)}. $$What are the correct coefficients?

Accepted Answer

$$1, 2, 1, 2$$

Question 3

If 22.0 moles of octane ($$\mathrm{C_8H_{18}}) $$are combusted, how many moles of $$\mathrm{CO_2$}$$ are produced? Use the balanced equation: $$2\mathrm{C_8H_{18}(l)} + 25\mathrm{O_2$(g)} \rightarrow 16\mathrm{CO_2$(g)} + 18\mathrm{H_2O(g)}.$$

Accepted Answer

176 moles

Question 4

A reaction mixture contains 42.5 g Mg and 33.8 g $$\mathrm{O_2$}. $$Using the reaction $$2\mathrm{Mg(s)} + \mathrm{O_2$(g)} \rightarrow 2\mathrm{MgO(s)}$$, which is the limiting reactant?

Accepted Answer

$$\mathrm{O_2$}$$

Question 5

Which of the following is the correct formula for calculating percent yield?

Accepted Answer

$$\frac{	ext{actual yield}}{	ext{theoretical yield}} 	imes 100\%$$

Question 6

Which of the following ions, when present in a compound, always indicates the compound is soluble in water with no exceptions?

Accepted Answer

$$\mathrm{NO_3$^-}$$

Question 7

Which solution will conduct electricity?

Accepted Answer

1.0 M $$\mathrm{KBr}$$

Question 8

What is the net ionic equation for the reaction between aqueous solutions of $$\mathrm{Pb(NO_3$)_2}$$ and $$\mathrm{KCl}$$?

Accepted Answer

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

Question 9

A chemist wants to prepare 5.5 L of a 0.300 M $$\mathrm{$$CaCl_2$$}$$ solution. What mass of $$\mathrm{$$CaCl_2$$} ($$molar mass = 110.98 g/mol) should be used?

Accepted Answer

182 g

Question 10

Which of the following best describes a strong electrolyte?

Accepted Answer

A substance that completely dissociates into ions in water.

Question 11

Which of the following reactions is a redox reaction?

Accepted Answer

$$2\mathrm{Na(s)} + \mathrm{Cl_2$(g)} \rightarrow 2\mathrm{NaCl(s)}$$

Question 12

Which of the following is the correct net ionic equation for the neutralization of hydrochloric acid with sodium hydroxide?

Accepted Answer

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

Question 13

A 10.0 mL sample of 0.20 M HBr is titrated with 0.10 M NaOH. What volume of NaOH is required to reach the equivalence point?

Accepted Answer

20.0 mL

Question 14

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

Accepted Answer

It is the reactant that is completely consumed and determines the maximum amount of product formed.

Question 15

Which of the following is a spectator ion in the reaction: $$\mathrm{$$AgNO_3$$(aq) + NaI(aq) \rightarrow AgI(s) + $$NaNO_3$$(aq)}$$?

Accepted Answer

$$\mathrm{NO_3$^-}$$

Question 16

Which metal is most easily oxidized according to the activity series?

Accepted Answer

Na

Question 17

What is the molarity of a solution prepared by dissolving 3.25 mol LiCl in 2.78 L of solution?

Accepted Answer

1.17 M

Question 18

Which of the following best describes a precipitation reaction?

Accepted Answer

A reaction in which a solid forms when two solutions are mixed.

Question 19

Which of the following compounds is insoluble in water?

Accepted Answer

$$\mathrm{AgCl}$$

Chemical Reactions, Quantities, and Solutions: Study Notes for General Chemistry

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