$4.0 \, g$ of caustic soda is dissolved in $100 \, mL$ of solution. The normality of the solution is: (in $, N$)

$7.8 \ g$ of a compound having molecular formula $C_6H_6$,on reacting with $CH_3COCl / AlCl_3$ gives $8.4 \ g$ of a product which has molecular formula $C_8H_8O$. Calculate the percentage yield of the product $C_8H_8O$. (Given atomic weights of $H$,$C$ and $O$ respectively are $1$,$12$ and $16$) (in $\%$)

The mass of iron converted into $Fe_3O_4$ by the action of $18\text{ g}$ of steam is : (Given: Molar mass of $H$, $O$ and Fe are $1$, $16$ and $56\text{ g mol}^{-1}$ respectively). Assume iron is present in excess: (in $\text{ g}$)

The right option for the mass of $CO_2$ produced by heating $20 \ g$ of $20 \%$ pure limestone is $........ \ g$ (Atomic mass of $Ca = 40$) $[CaCO_3 \stackrel{1200 \ K}{\longrightarrow} CaO + CO_2]$

$0.01$ mole of iodoform $(CHI_3)$ reacts with $Ag$ to produce a gas whose volume at $NTP$ is ............. $mL$.
$2CHI_3 + 6Ag \to 6AgI_{(s)} + C_2H_{2(g)}$

If $8 \ g$ of $NaOH$ is dissolved in $1 \ L$ of solution,its molarity will be ....... $M$.