Question

Strong acids and bases completely dissociate in water. Use the table in the introduction to classify the following chemical compounds as strong acids, weak acids, strong bases, and weak bases.

Part A

H3PO4(aq) and KOH(aq)

Express your answer as a chemical equation including phases.

Part B

HI(aq) and LiOH(aq)

Express your answer as a chemical equation including phases.

Part C

HNO3(aq) and Cu(OH)2(s)

Express your answer as a chemical equation including phases.

Answer 1

Part A

H3PO4(aq) and KOH(aq)

H3PO4 is strong acid.

H3PO4(aq) + H2O(l) --> H3O+(aq) + H2PO4-(aq)

The phosphoric acid donates a proton (H+) to the water and the water accepts a proton become H3O+ (hydronium ion) and because the phosphoric acid loses a proton's positive charge it becomes H2PO4-.

Potassium hydroxide is a strong base.
KOH_(s) -----> K⁺_(aq)  + OH^-_(aq)
Water doesn't participate directly in the reaction, so you can leave out the H2O on both sides. Because KOH is a strong base, it's pretty accurate to just have the arrow pointing one way in the reaction -- almost all of the KOH disassociates.

Part B

HI(aq) and LiOH(aq)

HI is strong acid

When it is dissolved in water it forms hyroiodic acid which is the strongest one of the halogen acids due to the high degree of ionization.
HI(aq) ------> H^+(aq) + I^-(aq)

Sometimes, the acidic property of the substance is shown by the formation of hydronium ion;
HI(g) + H2O(l) -----> H3O^+(aq) + I^-(aq)
This is one of the net ionic equations.
The other one is obtained by adding the first two equations:
HI(g) ------> H^+(aq) + I^-(aq)

LiOH is strong base.

LiOH(s) → Li+(aq) + OH-(aq)

Part C

HNO3(aq) and Cu(OH)2(s)

HNO3 is strong acid.

HNO3(aq) + H2O(l) → H3O+(aq) + NO3–(aq)

Copper hydroxide acts as a weak base in aqueous solution. It not dissolves in water.