Question
Mention important characteristics of acids.
Solution
Characteristics of acids:
(i) They are sour in taste.
(ii) They turn blue litmus to red.
(iii) Acids react with metals to evolve hydrogen gas.
2HCl + Mg → MgCl2 + H2 ↑
H2SO4 + Zn → ZnSO4 + H2 ↑
2HCl + 2Na → 2NaCl + H2 ↑
(iv) Acids react with bases to form salt and water. This is called neutralisation.
HCl + NaOH → NaCl + H2O
H2SO4 + Ca(OH)2 → CaSO4 + 2H2O
(v) Acids react with basic oxides to form salt and water.
CaO + 2HCl → CaCl2 + H2O
Na2O + H2SO4 → Na2SO4 + H2O
(vi) Acids react with carbonates to form salt, water and carbon dioxide.
CaCO3 + 2HCl → CaCl2 + H2O + CO2 ↑
MgCO3 + H2SO4 → MgSO4 + H2O + CO2 ↑
