Deck 4: Chemical Reactions

Question 1

Metals react with oxygen gas to produce oxides with the general formula M_xO_y. Write a balanced chemical equation for the reaction of titanium with oxygen to yield titanium(IV) oxide.

A) 4 Ti(s) + O₂(g) → 2 Ti₂O(s)
B) Ti(s) + O₂(g) → TiO₂(s)
C) 2 Ti(s) + O₂(g) → 2 TiO(s)
D) Ti(s) + O(g) → TiO(s)
E) 8 Ti(s) + O₂(g) → 2 Ti₄O(s)

Answer 1

Ti(s) + O₂(g) → TiO₂(s)

Question 2

Which one of the statements below is false concerning the following reaction: NH₃(g) + H₂O $( \ell )$ $\rightleftharpoons$ NH₄⁺(aq) + OH?(aq)

A) The double arrows indicate that ammonia, NH₃, is only very slightly soluble in water.
B) The reaction is reversible.
C) When NH₃ is added to H₂O, NH₄⁺ and OH? ions are produced in a 1:1 ratio.
D) When solutions of NH₄⁺ and OH^- are mixed, some ammonia is produced.
E) Ammonia partially reacts with water.

Answer 2

The double arrows indicate that ammonia, NH₃, is only very slightly soluble in water.

Question 3

If an aqueous solution of _____ is added to a mixture of Pb²⁺ and Ba²⁺, the lead ion will precipitate, but the barium ion will remain in solution.

A) NaOH
B) Na₂SO₄
C) K₃PO₄
D) KCO₃
E) NaF

Answer 3

NaOH

Question 4

Which of the following reactions best describes the dissolution of solid CsOH(s) in water?

A) CsOH(s) + H₂O(l) → CsO^-(aq) + H₃O⁺(aq)
B) CsOH(s) → CsO^-(aq) + H⁺(aq)
C) CsOH(s) → Cs⁺(aq) + OH^-(aq)
D) CsOH(s) → CsO⁺(aq) + H^-(aq)
E) CsOH(s) → CsOH(aq)

Question 5

What is the balanced chemical equation for the complete combustion of benzoic acid, C₆H₅CO₂H, to form carbon dioxide and water?

A) C₆H₅CO₂H(s) → 6 C(s) + CO₂(g) + 3 H₂(g)
B) C₆H₅CO₂H(s) → 7 CO₂(g) + 3 H₂O(g)
C) C₆H₅CO₂H(s) + O₂(g) → CO₂(g) + H₂O(g)
D) C₆H₅CO₂H(s) + 8 O₂(g) → 7 CO₂(g) + 3 H₂O(g)
E) 2 C₆H₅CO₂H(s) + 15 O₂(g) → 14 CO₂(g) + 6 H₂O(g)

Question 6

Which anion will form a precipitate with K⁺?

A) Cl^-
B) SO₄^2-
C) C₂H₃O₂^-
D) S^2-
E) none

Question 7

All of the following compounds are insoluble in water except _____.

A) BaCO₃
B) PbF₂
C) Fe(OH)₃
D) Ni(ClO₄)₂
E) PbCrO₄

Question 8

Which one of the following equations is properly balanced?

A) Sn + 4HNO₃ → SnO₂ + 4NO₂ + 2H₂O
B) 2Na₂SO₄ + 3Bi(NO₃)₃ → Bi₂(SO₄)₃ + 9NaNO₃
C) CH₃CHO + 3O₂ → 2CO₂ + 2H₂O
D) NH₄NO₃ → 2H₂O + N₂
E) Na₂CO₃ + 2H₂SO₄ → Na₂SO₄ + 2H₂O + CO₂

Question 9

A precipitate is expected when an aqueous solution of sodium iodide is added to an aqueous solution of

A) calcium nitrate.
B) barium hydroxide.
C) lead perchlorate.
D) iron(II) chloride.
E) sodium sulfate.

Question 10

Which of the following compounds is soluble in water?

A) Fe₂O₃
B) Rb₂O
C) BaS
D) Hg₂I₂
E) ZnO

Question 11

Which of the following ions is most likely to form an insoluble compound when combined with sulfate ion?

A) Sr²⁺
B) I^-
C) K⁺
D) Na⁺
E) S^2-

Question 12

A precipitate will form when aqueous Pb(NO₃)₂ is added to an aqueous solution of ____.

A) Cu(NO₃)₂
B) NaI
C) NaCH₃CO₂
D) Pb(ClO₄)₂
E) KNO₃

Question 13

The reaction of chlorine molecule with potassium iodide yields iodine molecule and potassium chloride. Write a balanced chemical equation for this reaction.

A) Cl₂(g) + KI(s) → I(s) + KCl₂(s)
B) Cl₂(g) + 2 KI(s) → I₂(s) + 2 KCl(s)
C) Cl₂(g) + KI₂(s) → I₂(s) + KCl₂(s)
D) Cl(g) + KI(s) → I(s) + KCl(s)
E) Cl₂(g) + 2 K₂I(s) → I₂(s) + 2 K₂Cl(s)

Question 14

The products of the complete combustion of octane, C₈H₁₈, are carbon dioxide and water. Write a balanced chemical equation for this reaction.

A) C₈H₁₈( $\ell$ ) ? 8 C(s) + 9 H₂(g)
B) C₈H₁₈( $\ell$ ) + 25 O₂(g) ? 8 CO₂(g) + 9 H₂O(g)
C) 2 C₈H₁₈( $\ell$ ) + 25 O₂(g) ? 16 CO₂(g) + 18 H₂O(g)
D) C₈H₁₈( $\ell$ ) + 16 O₂(g) ? 8 CO₂(g) + 9 H₂(g)
E) 2 C₈H₁₈( $\ell$ ) + 17 O₂(g) ? 16 CO(g) + 18 H₂O(g)

Question 15

All of the following compounds are soluble in water except ____.

A) CoCO₃
B) Cs₂CO₃
C) (NH₄)₂CO₃
D) K₂CO₃
E) Na₂CO₃

Question 16

A precipitate will form when aqueous nickel(II) chloride is added to an aqueous solution of ____.

A) SrI₂
B) Cu(NO₃)₂
C) KOH
D) Na₂SO₄
E) NaBr

Question 17

Which of the following compounds is soluble in water?

A) Al₂S₃
B) Cs₂O
C) CaS
D) Hg₂Cl₂
E) NiO

Question 18

Which of the following equations is not balanced?

A) 2Sb₂OS₂ + 10O₂ → 2Sb₂O₅ + 4SO₃
B) (NH₄)₂Cr₂O₇ → N₂ + 4H₂O + Cr₂O₃
C) C₁₂H₂₂O₁₁ + 12O₂ → 12CO₂ + 11H₂O
D) 2NaCl + Pb(NO₃)₂ → PbCl₂ + 2NaNO₃
E) Fe₃O₄ + 3CO → 3Fe + 3CO₂

Question 19

Which of the following compounds is insoluble in water?

A) NH₄Br
B) KBr
C) FeCl₂
D) Hg₂Br₂
E) LiBr

Question 20

Which anion will form a precipitate with Ba²⁺?

A) Cl^-
B) SO₄^2-
C) C₂H₃O₂^-
D) Br^-
E) None of these

Question 21

Which of the following products will form on mixing aqueous solutions of Cu(NO₃)₂ and NaOH?

A) Cu(OH)₂(s), Na⁺(aq), and NO₃?(aq)
B) Cu(OH)₂(s) and NaNO₃(s)
C) Cu₂(OH)₂(aq) and NaNO₃(aq)
D) Cu(OH)₂(aq) and NaNO₃(s)
E) Cu(OH)₂(s), N₂(g), and H₂O( $\ell$ )

Question 22

What is the net ionic equation for the reaction of aqueous sodium hydroxide and aqueous iron(II) chloride?

A) Na⁺(aq) + OH^-(aq) → NaOH(s)
B) Na⁺(aq) + Cl^-(aq) → NaCl(s)
C) Fe²⁺(aq) + 2 OH^-(aq) → Fe(OH)₂(s)
D) Fe²⁺(aq) + OH^-(aq) → FeOH⁺(s)
E) Fe²⁺(aq) + 2 Cl^-(aq) → FeCl₂(s)

Question 23

Which of the following is a weak base in aqueous solution?

A) RbCl
B) KOH
C) NH₃
D) HBr
E) Sr(OH)₂

Question 24

Which of the following is a strong acid in aqueous solution?

A) HOCH₂CH₂OH
B) Ca(OH)₂
C) H₃PO₄
D) NH₃
E) HClO₄

Question 25

When solutions of barium iodide and lithium sulfate are mixed, the spectator ions in the resulting precipitation reaction are

A) only SO₄^2-.
B) both Li⁺ and I^-.
C) only I^-.
D) only Li⁺.
E) only Ba²⁺.

Question 26

What is the balanced equation for carbonate ion (CO₃^2-) acting as a Brønsted base in a reaction with water?

A) CO₃^2-(aq) + 3 H₂O( $\ell$ ) $\rightleftharpoons$ CO₄^4-(aq) + 2 H₃O⁺(aq)
B) CO₃^2-(aq) + H₂O( $\ell$ ) $\rightleftharpoons$ HCO₃^-(aq) + OH^-(aq)
C) CO₃^2-(aq) + H₂O( $\ell$ ) $\rightleftharpoons$ CO₂(g) + 2 OH^-(aq)
D) CO₃^2-(aq) + 2 H₂O( $\ell$ ) $\rightleftharpoons$ HCO₃^-(aq) + H₃O⁺(aq)
E) CO₃^2-(aq) + H₂O( $\ell$ ) $\rightleftharpoons$ H₂CO₄^2-(aq)

Question 27

Which of the following equation best represents the net ionic equation for the reaction between aqueous solutions of barium chloride and cesium sulfate?

A) 2 H⁺(aq) + 2 Cl^-(aq) → 2 HCl(g)
B) Ba²⁺(aq) + SO₄^2-(aq) → BaSO₄(s)
C) Ba²⁺(aq) + 2 Cl^-(aq) + 2 Cs⁺(aq) + SO₄^2-(aq) → BaSO₄(s) + 2 CsCl(aq)
D) BaCl₂(aq) + Cs₂SO₄(aq) → BaSO₄(s)+ 2 CsCl(aq)
E) None of these

Question 28

Write a balanced chemical equation for the reaction of aqueous solutions of magnesium chloride and potassium phosphate.

A) MgCl₂(aq) + K₃PO₄(aq) → K₃Mg(s) + PO₄Cl₂(aq)
B) 3 MgCl₂(aq) + 2 K₃PO₄(aq) → 3 K₂Mg(s) + 2 PO₄Cl₃(aq)
C) MgCl(aq) + KPO₄(aq) → MgPO₄(s) + KCl(aq)
D) MgCl₂(aq) + 2 KPO₄(aq) → Mg(PO₄)₂(s) + 2 KCl(aq)
E) 3 MgCl₂(aq) + 2 K₃PO₄(aq) → Mg₃(PO₄)₂(s) + 6 KCl(aq)

Question 29

Write a balanced chemical equation for the reaction of aqueous solutions of sodium sulfide and zinc(II) chloride.

A) Na₂S(aq) + ZnCl₂(aq) → ZnS(s) + 2 NaCl(aq)
B) Na₂S(aq) + ZnCl₂(aq) → ZnS(s) + 2 NaCl(s)
C) Na₂S(aq) + ZnCl₂(aq) → Na₂Zn(s) + SCl₂(aq)
D) Na₂S(aq) + ZnCl₂(aq) → Na₂Zn(aq) + SCl₂(g)
E) None of these

Question 30

Which of the following compounds is a weak acid in aqueous solution?

A) HCl
B) H₃PO₄
C) HNO₃
D) HClO₄
E) H₂SO₄

Question 31

Write a balanced equation for the reaction that occurs when hydrogen sulfate ion behaves as a Brønsted-Lowry acid in water.

A) HSO₄^-(aq) + H₂O( $\ell$ ) $\rightleftharpoons$ H₂SO₄(aq) + H₃O⁺(aq)
B) SO₄^2-(aq) + H₂O( $\ell$ ) $\rightleftharpoons$ HSO₄^-(aq) + OH^-(aq)
C) HSO₄^-(aq) + H₂O( $\ell$ ) $\rightleftharpoons$ SO₄^2-(aq) + H₃O⁺(aq)
D) HSO₄^-(aq) + H₂O( $\ell$ ) $\rightleftharpoons$ H₂SO₄(aq) + OH^-(aq)
E) H₂SO₄(aq) + H₂O( $\ell$ ) $\rightleftharpoons$ HSO₄^-(aq) + H₃O⁺(aq)

Question 32

When aqueous solutions of calcium iodide, CaI₂, and silver nitrate, AgNO₃, are combined, which of the following statements below describes what occurs:

A) A precipitate of Ca(NO₃)₂ forms
B) A precipitate of AgI forms
C) Both Ca(NO₃)₂ and AgI precipitate
D) No precipitate will form

Question 33

Nitric acid is the product of the reaction of ____ and H₂O.

A) SO₃
B) NO₂
C) N₂
D) NH₃
E) N₃^-

Question 34

Which of the following compounds cannot be depicted as the individual ions on the reactant side in a complete ionic reaction?

A) CsOH
B) HCl
C) Ca(NO₃)₂
D) CaCO₃
E) Ti(NO₃)₃

Question 35

What base results when K₂O reacts with water?

A) H₃O⁺(aq)
B) KH(aq)
C) O^2-(aq)
D) KOH(aq)
E) KO^-(aq)

Question 36

What is the net ionic equation for the neutralization of hydrochloric acid with aqueous potassium hydroxide?

A) H⁺(aq) + OH^-(aq) ? H₂O( $\ell$ )
B) H⁺(aq) + Cl^-(aq) + K⁺(aq) + OH^-(aq) ? KCl(aq) + H₂O( $\ell$ )
C) H⁺(aq) + Cl^-(aq) + K⁺(aq) + OH^-(aq) ? HCl(aq) + KOH(aq)
D) HCl(aq) + K⁺(aq) + OH^-(aq) ? KCl(aq) + H₂O( $\ell$ )
E) HCl(aq) + KOH(aq) ? KCl(aq) + H₂O( $\ell$ )

Question 37

If an aqueous solution of ____ is added to a mixture of F^- and SO₄^2-, the fluoride ion will precipitate, but the sulfate ion will remain in solution.

A) LiBr
B) HNO₃
C) Pb(ClO₄)₂
D) MgNO₃
E) AlCl₃

Question 38

Which of the following would not be depicted as the individual ions on the reactant side of a complete ionic reaction?

A) LiOH
B) HBr
C) SrCl₂
D) CH₃COOH
E) CoCl₃

Question 39

Which of the following compounds acts as a strong base in an aqueous solution?

A) HOCH₂CH₂OH
B) Sr(OH)₂
C) H₃PO₄
D) NH₃
E) HNO₃

Question 40

Which of the following equations best represents the balanced net ionic equation for the reaction between aqueous solutions of ammonium phosphate and iron(II) nitrate are mixed?

A) 3 Fe²⁺(aq) + 2 PO₄^3-(aq) → Fe₃(PO₄)₂(s)
B) 2 NH₄⁺(aq) + Fe(NO₃)₂(aq) → 2 NH₄NO₃(aq) + Fe²⁺(aq)
C) 3 Fe²⁺(aq) + 2 PO₄^3-(aq) → Fe₃(PO₄)₂(aq)
D) 2 (NH₄)₃PO₄(aq) + 3 Fe²⁺(aq) → Fe₃(PO₄)₂(s) + 6 NH₄⁺(aq)
E) 2 (NH₄)₃PO₄(aq) + 3 Fe(NO₃)₂(aq) → Fe₃(PO₄)₂(s) + 6 NH₄NO₃(aq)

Question 41

The net ionic equation for the reaction of calcium carbonate with nitric acid is

A) CaCO₃(s) + 2H⁺(aq) ? Ca²⁺(aq) + CO₂(g) + H₂O( $\ell$ ).
B) Ca²⁺(aq) + CO₃^2-(aq) + 2H⁺(aq) + 2NO₃^-(aq) ? Ca(NO₃)₂(aq) + CO₂(g) + H₂O( $\ell$ ).
C) CaCO₃(s) + 2HNO₂(aq) ? Ca²⁺(aq) + 2NO₂^-(aq) + CO₂(g) + H₂O( $\ell$ ).
D) Ca(HCO₃)₂(s) + 2HNO₃(aq) ? Ca²⁺(aq) + 2NO₃^-(aq) + CO₂(g) + 2H₂O( $\ell$ ).
E) CaCO₃(s) + 2HNO₃(aq) ? Ca²⁺(aq) + 2NO₃^-(aq) + CO₂(g) + H₂O( $\ell$ ).

Question 42

Which of the following is the correct net ionic equation for the reaction between aqueous ammonia and hydrobromic acid?

A) HBr(aq) + NH₃(aq) ? NH₄Br(aq)
B) H⁺(aq) + OH^-(aq) ? H₂O( $\ell$ )
C) HBr(aq) + OH^-(aq) ? Br^-(aq) + H₂O( $\ell$ )
D) H⁺(aq) + NH₃(aq) ? NH₄⁺(aq)
E) H⁺(aq) + Br^-(aq) + NH₃(aq) ? NH₄⁺(aq) + Br^-(aq)

Question 43

What are the spectator ions in the reaction between aqueous hydroiodic acid and aqueous sodium hydroxide?

A) Na⁺ only
B) H⁺ and OH^-
C) Na⁺ and I^-
D) I^- only
E) H⁺, I^-, Na⁺, and OH^-

Question 44

Which species in the reaction below undergoes reduction?
H₂O(g) + CO(g) ? H₂(g) + CO₂(g)

A) H₂O
B) CO
C) H₂
D) CO₂
E) None

Question 45

Hydrocyanic acid, HCN, is a weak acid. Write a net ionic equation for the reaction of aqueous hydrocyanic acid and aqueous sodium hydroxide.

A) HCN(aq) + NaOH(aq) ? Na⁺(aq) + CN^-(aq) + H₂O( $\ell$ )
B) HCN(aq) + H₂O(aq) ? CN^-(aq) + H₃O⁺(aq)
C) H⁺(aq) + OH^-(aq) ? H₂O( $\ell$ )
D) HCN(aq) + OH^-(aq) ? CN^-(aq) + H₂O( $\ell$ )
E) H⁺(aq) + NaOH(aq) ? Na⁺(aq) + H₂O( $\ell$ )

Question 46

The oxidation number of chlorine is highest in which of the following?

A) HCl
B) Cl₂
C) HClO₂
D) NaClO₃
E) ClO₂−

Question 47

What is the oxidation number of P in NH₄(H₂PO₄)?

A) -2
B) -3
C) 5
D) 1
E) 3

Question 48

In the reaction of acetic acid with aqueous lithium hydroxide, what is the spectator ion?

A) OH^-(aq)
B) There is no spectator ion.
C) C₂H₃O₂^-(aq)
D) Li⁺(aq)
E) H⁺(aq)

Question 49

Write a balanced net ionic equation for the reaction of aqueous solutions of baking soda (NaHCO₃) and acetic acid.

A) HCO₃^-(aq) + CH₃CO₂H(aq) ? CH₃CO₂^-(aq) + H₂O( $\ell$ ) + CO₂(g)
B) 2 NaHCO₃(aq) + CH₃CO₂H(aq) ? 2 Na₂CO₃(aq) + CH₄(aq) + 2H₂O( $\ell$ ) + CO₂(g)
C) NaHCO₃(aq) + H⁺(aq) ? H₂CO₃(s) + Na⁺(aq)
D) HCO₃^-(aq) + H⁺(aq) ? H₂O( $\ell$ ) + CO₂(g)
E) HCO₃^-(aq) + H⁺(aq) ? H₂CO₃(aq)

Question 50

Which species is reduced in the reaction below?
I^-(aq) + ClO^-(aq) ? IO^-(aq) + Cl^-(aq)

A) I^-
B) H₂O
C) Cl^-
D) IO^-
E) ClO^-

Question 51

Write a balanced chemical equation for the reaction of aqueous solutions of ammonium sulfate and sodium hydroxide.

A) (NH₄)₂SO₄(aq) + 2 NaOH(aq) ? 2 NH₄OH(aq) + SO₃(g) + Na₂O(aq)
B) (NH₃)₂SO₄(aq) + NaOH(aq) ? 2 NH₃(g) + NaOHSO₄(aq)
C) (NH₃)₂SO₄(aq) + 2 NaOH(aq) ? 2 NH₃(g) + Na₂SO₄(aq) + 2 OH?(aq)
D) (NH₄)₂SO₄(aq) + 2 NaOH(aq) ? 2 NH₄⁺(g) + Na₂SO₄(aq) + 2 OH?(aq)
E) (NH₄)₂SO₄(aq) + 2 NaOH(aq) ? 2 NH₃(g) + 2 H₂O( $\ell$ ) + Na₂SO₄(aq)

Question 52

In the reaction below, which species is oxidized? 3 Rb₂S(s) + 8 H⁺(aq) + 2 NO₃^-(aq) → 6 Rb⁺(aq) + 3 S(s) + 2 NO(g) + 4 H₂O

A) NO₃^-
B) Rb₂S
C) Rb⁺
D) NO
E) H⁺

Question 53

Metal oxides react with water to produce ____.

A) bases
B) hydrogen gas
C) oxygen gas
D) acids
E) hydronium ions

Question 54

Which of the following is/are spectator ions in the reaction between aqueous nitric acid and ammonia?

A) H⁺
B) NO₃^-
C) H⁺ and NH₄⁺
D) NO₃^- and NH₄⁺
E) H⁺, NO₃^-, and NH₄⁺

Question 55

Which molecule in the reaction below is the oxidizing agent? 2 C₂H₆(g) + 7 O₂(g) → 4 CO₂(g) + 6 H₂O(g)

A) C₂H₆
B) O₂
C) H₂O
D) CO₂
E) None

Question 56

What is the oxidation number of each atom in sodium hydrogen carbonate, NaHCO₃?

A) Na = +1, H = -1, C = +6, and O = -2
B) Na = +1, H = +1, C = +4, and O = -2
C) Na = +1, H = -1, C = +2, and O = -2
D) Na = -1, H = +1, C = 0, and O = -2
E) Na = +1, H = -1, C = 0, and O = 0

Question 57

Which of the following is a weak electrolyte in aqueous solution?

A) Mg(OH)₂
B) NH₃
C) LiOH
D) KOH
E) Sr(OH)₂

Question 58

What is the oxidation number of Fe in BaFeO₄?

A) 2
B) -2
C) 6
D) +3
E) 0

Question 59

Which of the following elements generally acts as an oxidizing agent?

A) Br₂
B) H₂
C) Fe
D) C
E) Li

Question 60

Which of the following compounds will produce a basic solution when dissolved in water?

A) CaO
B) NaHSO₄
C) CO₂
D) SO₂
E) KCl

Question 61

The net ionic equation for the reaction of barium chloride and sodium sulfate is shown below.
Ba²⁺(aq) + SO₄^2-(aq) → BaSO₄(s)
Chloride and sodium ions are referred to as ________ ions because they are not involved in the reaction.

Question 62

________ acid is produced in a larger quantity than any other chemical in the United States. This chemical is used in the production of fertilizers, pigments, alcohol, paper and detergents.

Question 63

Which of the following compounds is a basic oxide?

A) CO₂
B) SO₂
C) SO3
D) NO2
E) CaO

Question 64

Identify a true statement about oxidation numbers.

A) Each atom in an element has an oxidation number of 1.
B) For monoatomic ions, the oxidation number is equal to the charge on the ion.
C) The oxidation number of H is 0 in most of the compounds.
D) The oxidation number of O is +2 in most of the compounds.
E) Fluorine always has an oxidation number of +1 in most of the compounds.

Question 65

Which of the following is not an oxidation?reduction reaction?

A) CaCO₃(s) ? CaO(s) + CO₂(g)
B) 2 Na(s) + Br₂(g) ? 2 NaBr(g)
C) Fe(s) + 2 HCl(aq) ? FeCl₂(aq) + H₂(g)
D) 2 C(s) + O₂(g) ? 2 CO(g)
E) 2 H₂O( $\ell$ ) ? 2 H₂(g) + O₂(g)

Question 66

_____-oxides produce acids when reacted with water.

Question 67

If an aqueous sodium hydroxide solution is left in contact with air, the concentration of hydroxide ion gradually decreases. The process can be hastened if a person exhales over a sodium hydroxide solution. Write a balanced chemical equation that describes the process by which the hydroxide ion concentration decreases.

Question 68

A solution is a homogeneous mixture composed of one or more ____________ dissolved in a solvent.

Question 69

A(n) _____ agent gains electrons in an oxidation-reduction reaction.

Question 70

Give the name of an acidic oxide and write a balanced chemical equation for the reaction of the oxide with water.

Question 71

Ionic and molecular compounds that form ions in aqueous solution are called _____.

Question 72

Which of the following chemical equations is an acid-base reaction?

A) Ba(OH)₂(aq) + K₂SO₄(aq) → BaSO₄(s) + 2 KOH(aq)
B) 3 NaOH(aq) + AlCl₃(aq) → Al(OH)₃(s) + 3 NaCl(aq)
C) 2 H⁺(aq) + Zn(s) → H₂(g) + Zn²⁺(aq)
D) 2 HCl(aq) + Pb(NO₃)₂(aq) → PbCl₂(s) + 2 HNO₃(aq)
E) H₃PO₄(aq) + NH₃(aq) → NH₄⁺(aq) + H₂PO₄−(aq)