Question

A white solid X on heating gives a white solid Y and an acidic gas Z. Gas Z is also given out when X reacts with an acid. The compound Y is also formed if caustic soda is left open in the atmosphere. X, Y and Z are :

• A. $X-NaHC{O}_3,Y-N{a}_{2}C{O}_3,Z-C{O}_2$
• B. $X-N{a}_{2}C{O}_3,Y-NaOH,Z-C{O}_2$
• C. $X-NaHC{O}_3,Y-NaHC{O}_3,Z-C{O}_2$
• D. $X-NaOH,Y-NaHC{O}_3,Z-C{O}_2$

Answer 1

The correct option is A $X-NaHC{O}_3,Y-N{a}_{2}C{O}_3,Z-C{O}_2$

carbon dioxide(Z) is an acidic oxide is produced on heating sodium bicarbonate (X) while the formation of sodium carbonate (Y).

$2NaHC{O}_3\left(X\right)\to {Na}_{2}C{O}_3\left(Y\right)+C{O}_2\left(Z\right)+H_{2}O$

The carbon dioxide gas is also given out when sodium bicarbonate reacts with an acid.

$NaHC{O}_3\left(X\right)+HCl\to NaCl+C{O}_2\left(Z\right)+H_{2}O$

The sodium carbonate is formed if caustic soda is left open in the atmosphere.

$2NaOH+C{O}_2\left(Atmosphere\right)\to {Na}_{2}C{O}_3\left(Y\right)+H_{2}O$