The moles of methane required to produce $81 \ g$ of water after complete combustion is $.... \times 10^{-2} \ mol.$ [nearest integer]

Consider the reaction shown below where $6.1 \,g$ of benzoic acid is used to obtain $7.8 \,g$ of $m$-bromobenzoic acid. The percentage yield of the product is ....... .
(Round off to the Nearest integer) [Given : Atomic masses : $C = 12.0 \,u, H = 1.0 \,u, O = 16.0 \,u, Br = 80.0 \,u$]

$23 \ g$ of $Na$ metal reacts with ethanol to produce which of the following?

The conversion of oxygen to ozone occurs to the extent of $15\%$ only. The mass of ozone that can be prepared from $67.2 \ L$ of oxygen at $1 \ atm$ and $273 \ K$ will be ............ $g$.

Match the following items in List-$I$ with the corresponding results in List-$II$ (at $STP$):

List-$I$	List-$II$ (At $STP$)
$(A)$ $10 \ g \ CaCO_3 \xrightarrow{\Delta} \text{decomposition}$	$(i)$ $0.224 \ L \ CO_2$
$(B)$ $1.06 \ g \ Na_2CO_3 \xrightarrow{\text{Excess } HCl} \text{reaction}$	$(ii)$ $4.48 \ L \ CO_2$
$(C)$ $2.4 \ g \ C \xrightarrow{\text{Excess } O_2} \text{combustion}$	$(iii)$ $0.448 \ L \ CO_2$
$(D)$ $0.56 \ g \ CO \xrightarrow{\text{Excess } O_2} \text{combustion}$	$(iv)$ $2.24 \ L \ CO_2$
	$(v)$ $22.4 \ L \ CO_2$

At $S.T.P.$,$1 \ g$ $CaCO_3$ on decomposition gives $CO_2$ ............. $litres$.