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

	X	Y		Z
A	$NaHCO_{3}$	$Na_{2}CO_{3}$		$CO_{2}$
B	$Na_{2}CO_{3}$	NaOH		$CO_{2}$
C	$Na_{2}CO_{3}$	$NaHCO_{3}$		$CO_{2}$
D	NaOH	$NaHCO_{3}$		$CO_{2}$

• A. (A) NaHCO3, Na2CO3, CO2
• A. (B) Na2CO3, NaOH, CO2
• A. (C) Na2CO3, NaHCO3, CO2
• A. (D) NaOH, NaHCO3, CO2

Answer 1

: $\underset{(X)}{2NaHCO_{3}} \rightarrow \underset{(Y)}{Na_{2}CO_{3}} + \underset{(Z)}{CO_{2}} + H_{2}O$

$\underset{(X)}{NaHCO_{3}} + HCl \rightarrow NaCl + \underset{(Z)}{CO_{2}} + H_{2}O$

$2NaOH\underset{(atmosphere)}{+ CO_{2}} \rightarrow \underset{(Y)}{Na_{2}}CO_{3} + H_{2}O$