Question

Identify correctly matched sets:
I. NaHCO$_3$ - fire extinguisher
II. Na$_2$CO$_3$ - water softening
III. NaOH - purification of bauxite

• A. I, II only
• B. II, III only
• C. I, III only
• D. I, II, III

Hint:

Know industrial applications of common salts. Check chemical reactions for use. NaHCO$_3$, Na$_2$CO$_3$, NaOH have distinct roles.

Answer 1

The Correct Option is D

• NaHCO$_3$ decomposes releasing CO$_2$ → fire extinguisher.
• Na$_2$CO$_3$ precipitates Ca$^{2+}$, Mg$^{2+}$ → water softening.
• NaOH reacts with Al$_2$O$_3$ in bauxite → purification.