Question

Identify $W$, $X$, $Y$, and $Z$ respectively in the given reactions.
$CaCO_3 \xrightarrow{\Delta} W + X$
$W +H_2O \rightarrow Y$
$Y + Z \rightarrow NaOH +CaCO_3$

• A. $CaO$, $CO_2$, $CaCO_3$, $Na_2CO_3$
• B. $CO_2$, $Ca(OH)_2$, $Ca(HCO)_3$, $NaHCO_3$
• C. $CaO$, $CO_2$, $Ca(OH)_2$, $Na_2CO_3$
• D. $CO_2$, $CaO$, $H_2CO_3$, $Na_2CO_3$

Answer 1

Answer: (C)

$CaCO _3 \xrightarrow{\Delta} \underset{( W )}{ CaO }+\underset{( X )}{ CO _2}$
$\underset{(W)}{CaO} + H _2 O \rightarrow \underset{(Y)}{Ca ( OH )_2}$
$\underset{\text { (Y) }}{ Ca ( OH )_2}+\underset{\text { (Z) }}{ Na _2 CO _3} \rightarrow CaCO _3+2 NaOH$