If the density of methanol is $0.793 \ kg \ L^{-1}$,what volume is needed to prepare $2.5 \ L$ of a $0.25 \ M$ solution (in $mL$)?

The normality of orthophosphoric acid having purity of $70\%$ by weight and specific gravity $1.54$ would be ............. $N$.

Number of moles of oxygen gas evolved by electrolysis of $180 \ g$ of water?

$0.01\, M\, KMnO_{4}$ solution was added to $20.0\, mL$ of $0.05\, M$ Mohr's salt solution through a burette. The initial reading of $50\, mL$ burette is zero. The volume of $KMnO_{4}$ solution left in the burette after the end point is $.....\, mL$. (nearest integer)

If $1 \, mole$ of $H_3PO_x$ is completely neutralized by $80 \, g$ of $NaOH$,select the correct statement :-

Find the molecular weight of a solid containing $20\%$ by mole of $S$ atoms,whose $400\ g$ provides just sufficient $S$ atoms to produce enough $H_2SO_4$ to neutralise $100\ g$ $NaOH$.