Explain the reaction of dilute acids with metals and metal oxides.

(a) All the above are Neutralization Reactions.
Name of salts in reactions:
(b) (i) Sodium carbonate, (ii) Ammonium acetate,
(iii) Potassium nitrate, (iv) Sodium sulphate.

Chemical Reactions:
Marble is calcium carbonate. It reacts with HCl to give CO₂
CaCO₃ + 2HCl $\underset{ }{\to }$ CaCl₂ + CO₂ + H₂O
Marble                                             (A)

CO₂ when passed through lime water [Ca(OH)₂] gives a white precipitate of CaCO₃.
Ca(OH)₂ + CO₂(g) $\underset{ }{\to }$CaCO₃(s) + H₂O
                                             White ppt.
                                                  (B)
On passing excess CO₂, CaCO₃ dissolves forming soluble Ca(HCO₃)₂.
CaCO₃ + CO_{2 $\stackrel{+{\mathrm{H}}_2\mathrm{O}}{\to }$} Ca(HCO₃)₂ (aq)
                                   Calcium
                                   hydrogen
                                   carbonate
                                       (C)

A — Carbon dioxide
B — Calcium carbonate
C — Calcium hydrogen carbonate
                                   

Physical characteristics of acid and base are:

Acids are
(i) sour in taste.
(ii) change the colour of blue litmus to red.

Bases are
(i) bitter in taste.
(ii) change the colour of red litmus to blue.