$25 \ mL$ of $0.1 \ N \ NaOH$ solution neutralises $12.5 \ mL$ of $HCl$ solution. The amount of water needed to convert $500 \ mL$ of such $HCl$ solution to $0.1 \ N$ is (in $mL$)

Density of a $2.05 \ M$ solution of $H_2SO_4$ in water is $1.08 \ g/mL$. Find its Normality and molality.

If $1 \ g$ of each of the following gases are taken at $STP$,which of the gases will occupy $(a)$ greatest volume and $(b)$ smallest volume? $CO, H_2O, CH_4, NO$

When $100 \, mL$ of $1 \, M$ $NaOH$ and $10 \, mL$ of $10 \, N$ $H_2SO_4$ solutions are mixed,what will be the nature of the resulting solution?

Rearrange the following ($I$ to $IV$) in the order of increasing masses:
$(I)$ $0.5$ mole of $O_3$
$(II)$ $0.5 \, g$ atom of oxygen
$(III)$ $3.011 \times 10^{23}$ molecules of $O_2$
$(IV)$ $5.6 \, L$ of $CO_2$ at $STP$

$20 \ mL$ of $2 \ M$ $NaOH$ solution is added to $400 \ mL$ of $0.5 \ M$ $NaOH$ solution. The final concentration of the solution is $.......... \times 10^{-2} \ M$. $(Nearest \ integer)$.