The molality of a $10\%(\mathrm{v}/\mathrm{V})$ solution of di-bromine solution in ${\mathrm{CCl}}_4$ (carbon tetrachloride) is $\mathrm{x}$ '. $\mathrm{x}=$ $\_\_\_\_\_\times {10}^{-2}\mathrm{M}$. (Nearest integer)

[Given : molar mass of ${\mathrm{Br}}_2=160 \mathrm{g} {\mathrm{mol}}^{-1}$

atomic mass of $\mathrm{C}=12 \mathrm{g} {\mathrm{mol}}^{-1}$

atomic mass of $\mathrm{Cl}=35.5 \mathrm{g} {\mathrm{mol}}^{-1}$

density of dibromine $=3.2 \mathrm{g} {\mathrm{cm}}^{-3}$

density of $\left.{\mathrm{CCl}}_4=1.6 \mathrm{g} {\mathrm{cm}}^{-3}\right]$

$10.0 \mathrm{ml}$ of ${\mathrm{Na}}_2{\mathrm{CO}}_3$ solution is titrated against $0.2 \mathrm{M} \mathrm{HCl}$ solution. The following values were obtained in $5$ readings. $4.8 \mathrm{ml},4.9 \mathrm{ml},5.0 \mathrm{ml},5.0 \mathrm{ml}$ and $5.0 \mathrm{ml}$ 

Based on these readings, and convention of titrimetric estimation of concentration of ${\mathrm{Na}}_2{\mathrm{CO}}_3$ solution is ___ $\mathrm{mM}$.
(Round off to the Nearest integer)

Consider the above reaction where $6.1 \mathrm{g}$ of benzoic acid is used to get $7.8 \mathrm{g}$ of m-bromo benzoic acid. The percentage yield of the product is ___ .

(Round off to the Nearest integer)

[Given : Atomic masses : $\mathrm{C}=12.0 \mathrm{u}, \mathrm{H}:1.0 \mathrm{u}, \mathrm{O}:16.0 \mathrm{u}, \mathrm{Br}=80.0 \mathrm{u}$]

Consider the above reaction. The percentage yield of amide product is (Round off to the Nearest Integer). (Given : Atomic mass : $\mathrm{C}:12.0\mathrm{u},\mathrm{H}:1.0\mathrm{u}$ $\mathrm{N}:14.0\mathrm{u},\mathrm{O}:16.0\mathrm{u},\mathrm{Cl}:35.5\mathrm{u})$