Topic 8.2: Properties of acids and bases

Question 1

Equation of reaction of an acid with a metal

Answer 1

Metal + Acid => Salt + H2(g)

Question 2

Examples of reactions

Answer 2

Zn(s) + 2HCl(aq) => ZnCl2(aq) + H2(g)

Question 3

Which type of metals do acids react with?

Answer 3

a) Reactive metals (e.g., Ca / Mg / K / Zn)

b) No unreactive metals (e.g., Cu / Au / Ag)

Question 4

Neutralization reaction

Answer 4

Chemical reaction where a base and an acid react to form a salt and water

Question 5

Why are neutralization reactions exothermic? (3)

Answer 5

a) When a strong acid and a strong base are dissolved in water, they are completely dissociated into their ions.
b) The anions from the acid and the cations from the base remain in solution as spectator ions.
c) The only reaction that takes place is the reaction between hydronium and hydroxide ions to form water, and this reaction is exothermic.

Question 6

Equation of reaction of an acid with metal oxides and metal hydroxides

Answer 6

Acid + Base => Salt + Water

Question 7

Example of neutralization reaction between a metal hydroxide and an acid

Answer 7

HCl(aq) + NaOH(aq) => NaCl(aq) + H2O(l)

Question 8

Example of neutralization reaction between a metal oxide and an acid

Answer 8

2CH3COOH(aq) + CuO(s) => Cu(CH3COO)2(aq) + H2O(l)

Question 9

Equation of reaction of an acid with carbonate and hydrogen carbonate

Answer 9

Acid + Carbonate => Salt + H2O(l) + CO2(g)

Question 10

Example of neutralization reaction of an acid with carbonate base
Na2CO3(aq) + H2SO4(aq)

Answer 10

Na2SO4(aq) + H2O(l) + CO2(g)

Question 11

Example of neutralization reaction of an acid with hydrogen carbonate base
CH3COOH(aq) + KHCO3 (aq)

Answer 11

KCH3COO(aq) + H2O(l) + CO2(g)

Question 12

Example of reaction of ammonia with acid

NH3(aq) + HCl (aq)

Answer 12

NH4Cl(aq)

Question 13

Indicator definition (2)

Answer 13

a) Substances that have different color according to the concentration of H+ ions in the solution
b) Weak acids whose conjugates have different colors

Question 14

Common indicators (Acid => Base)

Answer 14

Methyl orange (Red => Yellow)
Litmus (Pink => Blue)
Phenolphthalein (Colorless => Pink)