Question 1

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

Accepted Answer

Evaporation of water

Question 2

Given the chemical equation $$2H_2 + O_2$ \rightarrow 2H_2O$$, which statement is TRUE about the law of conservation of mass?

Accepted Answer

The number and type of atoms are the same on both sides of the equation.

Question 3

What is the correct balanced equation for the reaction: $$C_2H_4 + O_2$ \rightarrow CO_2$ + H_2O$$?

Accepted Answer

$$C_2H_4 + 3O_2 \rightarrow 2CO_2 + 2H_2O$$

Question 4

Which type of reaction is represented by $$AB \rightarrow A + B$$?

Accepted Answer

Decomposition reaction

Question 5

In the reaction $$Zn(s) + $$CuSO_4$$(aq) \rightarrow $$ZnSO_4$$(aq) + Cu(s)$$, which element is oxidized?

Accepted Answer

Zinc

Question 6

What is the oxidation number of oxygen in $$H_2O_2$$?

Accepted Answer

$$-1$$

Question 7

Which of the following compounds is insoluble in water?

Accepted Answer

AgCl

Question 8

What is the net ionic equation for the reaction between $$Pb(NO_3$)_2(aq)$$ and $$2NaI(aq)$$?

Accepted Answer

$$Pb^{2+}(aq) + 2I^-(aq$$) \rightarrow $$PbI_2(s$$)$$

Question 9

Which of the following is a combustion reaction?

Accepted Answer

$$C_3H_8 + 5O_2 \rightarrow 3CO_2 + 4H_2O$$

Question 10

Which statement about acids and bases in aqueous solutions is correct?

Accepted Answer

Acids produce $$H^+$$ ions and bases produce $$OH^-$$ ions in water.

Question 11

What is the product of the neutralization reaction between $$HNO_3(aq$$)$$ and $$LiOH(aq)$$?

Accepted Answer

$$LiNO_3(aq) + H_2O(l$$)$$

Question 12

Which of the following is a double displacement reaction?

Accepted Answer

$$AB + CD \rightarrow AD + CB$$

Question 13

Which of the following best describes oxidation in a redox reaction?

Accepted Answer

Loss of electrons

Question 14

If $$Fe(s) + O_2$(g) \rightarrow Fe_2O_3(s)$$, what is the oxidation number of iron in $$Fe_2O_3$$?

Accepted Answer

$$+3$$

Question 15

Which of the following ions is most likely to be insoluble in water?

Accepted Answer

$$Pb^{2+}$$

Question 16

What is the complete ionic equation for the reaction: $$NaOH(aq) + HCl(aq) \rightarrow NaCl(aq) + H_2O(l)$$?

Accepted Answer

$$Na^+(aq) + OH^-(aq) + H^+(aq) + Cl^-(aq) \rightarrow Na^+(aq) + Cl^-(aq) + H_2O(l)$$

Question 17

Which of the following is a precipitation reaction?

Accepted Answer

$$Pb(NO_3$)_2(aq) + 2NaI(aq) \rightarrow $$PbI_2$$(s) + 2NaNO_3(aq)$$

Question 18

Which of the following best explains why $$AgCl is $$insoluble in water?

Accepted Answer

It forms strong ionic bonds that water cannot break.

Chemical Reactions: Classification, Equations, and Aqueous Solutions

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