$5 \, L$ of a gaseous mixture of ethane and propane are burnt to produce total $11 \, L$ of $CO_2$. Volume percent of $C_2H_6$ in the initial mixture is

$100 \, mL$ of a mixture of $NaOH$ and $Na_2SO_4$ is neutralized by $10 \, mL$ of $0.5 \, M$ $H_2SO_4$. Hence,the mass of $NaOH$ in $100 \, mL$ solution is ........... $g$.

Normality of $2 \, M$ sulphuric acid is

Under the same conditions,how many $mL$ of $1 \ M \ KOH$ and $0.5 \ M \ H_2SO_4$ solution,respectively,when mixed to form a total volume of $100 \ mL$,produce the maximum rise in temperature?

The molarity of pure water is ...... .

In an aqueous solution of $A_2B_3$,it undergoes complete ionization according to the reaction $A_2B_3 \rightleftharpoons 2A^{+3} + 3B^{-2}$. The concentration of $A^{+3}$ is equal to......