How many milliliters of water must be added to $10 \, mL$ of $10 \, N \, HNO_3$ to convert it into $0.1 \, N \, HNO_3$?

$40 \ mL$ of $0.1 \ N$ $KMnO_4$ is equivalent to $30 \ mL$ of $KHC_2O_4$ solution. How many $mL$ of $0.1 \ N$ $KOH$ are required to titrate $60 \ mL$ of the same $KHC_2O_4$ solution?

The normality of $1 \ M$ solution of $H_3PO_4$ will be.....$N$

At $STP$,for complete combustion of $3\, g$ of $C_2H_6$,the required volume of $O_2$ will be - ............. $litre$.

If a $100 \ mL$ solution contains $X \ g$ of $Na_2CO_3$ and its concentration is $Y \ M$,then $X$ and $Y$ are respectively ..............

The number of moles of $Br_2$ produced when two moles of potassium permanganate are treated with excess potassium bromide in aqueous acid medium is