Question 1

Which of the following is NOT considered evidence of a chemical reaction?

Accepted Answer

Bubbles form when water boils.

Question 2

What is the balanced chemical equation for the combustion of methane ($$\mathrm{CH_4$}) in $$oxygen?

Accepted Answer

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

Question 3

Which of the following best describes a precipitation reaction?

Accepted Answer

A reaction that forms a solid when two aqueous solutions are mixed.

Question 4

When sodium chloride ($$\mathrm{NaCl}) $$dissolves in water, what is present in the solution?

Accepted Answer

Only $$\mathrm{Na^+}$$ and $$\mathrm{Cl^-}$$ ions.

Question 5

Which of the following reactions is an example of an oxidation–reduction (redox) reaction?

Accepted Answer

Combustion of octane in an automobile engine.

Question 6

Which of the following compounds is insoluble in water according to the solubility rules?

Accepted Answer

$$\mathrm{AgCl}$$

Question 7

What is the net ionic equation for the reaction between aqueous solutions of silver nitrate ($$\mathrm{$$AgNO_3$$}) $$and sodium chloride ($$\mathrm{NaCl}$$)?

Accepted Answer

$$\mathrm{Ag^+(aq) + Cl^-(aq) \rightarrow AgCl(s)}$$

Question 8

Which of the following best describes a strong electrolyte?

Accepted Answer

A substance that completely dissociates into ions in solution.

Question 9

Which of the following is a double-displacement reaction?

Accepted Answer

$$\mathrm{2KI(aq) + Pb(NO_3$)_2(aq) \rightarrow 2KNO_3(aq) + $$PbI_2$$(s)}$$

Question 10

Which of the following is the correct sequence for balancing a chemical equation?

Accepted Answer

Balance elements that occur in only one compound on each side first, then balance free elements last.

Question 11

Which of the following is a real-life example of a gas evolution reaction?

Accepted Answer

Mixing baking soda and vinegar to make a volcano erupt.

Question 12

What is the main reason laundry detergents work better than soap in hard water?

Accepted Answer

They contain substances that remove calcium and magnesium ions by forming insoluble solids.

Question 13

Which of the following is the correct molecular equation for the reaction between potassium iodide ($$\mathrm{KI}) $$and lead(II) nitrate ($$\mathrm{Pb(NO_3$)_2}) in $$aqueous solution?

Accepted Answer

$$\mathrm{2KI(aq) + Pb(NO_3$)_2(aq) \rightarrow 2KNO_3(aq) + $$PbI_2$$(s)}$$

Question 14

Which of the following is a synthesis reaction?

Accepted Answer

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

Question 15

Which of the following is the best definition of a net ionic equation?

Accepted Answer

An equation showing only the species that actually participate in the reaction.

Question 16

Which of the following is a correct example of an acid–base reaction?

Accepted Answer

$$\mathrm{HCl(aq) + NaOH(aq) \rightarrow NaCl(aq) + H_2O(l)}$$

Question 17

Which of the following statements about chemical equations is TRUE?

Accepted Answer

Coefficients are used to balance the number of atoms on both sides.

Question 18

Which of the following is a decomposition reaction?

Accepted Answer

$$\mathrm{2H_2O(l) \rightarrow 2H_2(g) + O_2$(g)}$$

Chemical Reactions, Equations, and Aqueous Solutions: Study Notes for Introductory Chemistry

Guida di studio - Domande di pratica

Study guide - Flashcard