Chapter 9: Unit 8. Reactions of Acids and Bases

Bases Reactions:

• a. Reactions of the inorganic bases with the acids are producing salts and water:

Examples:

KOH(aq) + HCl(aq) ⇔KCl(aq) + H 2 O(l)

2 Fe(OH)3 (aq) + 3 H2SO4 (aq) ⇔ Fe2(SO4)3 (aq) + 6 H2O(l)

• b. Reactions of the organic bases with the acids are producing salts only and no water:

Examples:

CH3–NH2 + HCl(aq) ⇔ CH3–NH3+ + Cl–(aq)

Acids Reactions:

• a. Reactions of the acids with inorganic bases yield salt and water as shown in the above exmaple.
• b. Reactions of the acids with organic bases yield salt only and no water as shown in the above example.
• c. Reactions of the acids with metals yield hydrogen and salts:

Example:

2HCl(aq) + Mg(s)→MgCl2 (aq) + H2 (g)

• d. Reactions of the acids with the bicarbonates (hydrogen carbonate) yield salt, water and carbondioxide:

Example:

2HCl(aq) + Ca(HCO3)2 (s)→CaCl2 (aq) + 2H2O(l) + 2CO2 (g)

• e. Reactions of the acids with the carbonates yield salt, water and carbondioxide:

6HCl(aq) + Al2(CO3)3 (s) →2 AlCl3 (aq) + 3H2O(l) + 3CO2 (g)

The net chemical equations of the acids with hydroxidebases:

Example:

The complete molecular equation:

Cr(OH)3 (aq) + 3HNO3 (aq) →Cr(NO3)3 (aq) + 3H2O(l)

The complete ionic chemical equation:

Cr 3+ (aq) + 3OH–(aq) + 3H + (aq) + 3 NO 3–(aq) → Cr3+ (aq) + 3NO 3–(aq) + 3 H 2 O(l)

By cancelling out the spectator ions Cr3+ (aq) and NO3–(aq) from both sides of the chemical equation, one obtains the net ionic chemical equation.

The net ionic chemical equation:

3OH–(aq) + 3H + (aq) ⇔3H2O(l)

The net ionic chemical equation above represents the neutralization reaction (double replacement reaction) of acids with hydroxide bases.