$A$ mixture of $2.3 \ g$ formic acid and $4.5 \ g$ oxalic acid is treated with conc. $H_2SO_4$. The evolved gaseous mixture is passed through $KOH$ pellets. Weight of the remaining product at $STP$ is .......... $g$.

$60 \ mL$ $NaOH$ solution is required for complete neutralization of $0.98 \ g$ orthophosphoric acid. The concentration of $NaOH$ solution is ............. $M$.

The molecular formula of a commercial resin used for exchanging ions in water softening is $C_8H_7SO_3^- Na^+$ $(Mol. \ wt. 206)$. What would be the maximum uptake of $Ca^{2+}$ ions by the resin when expressed in mole per gram resin?

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

In the petroleum industry,a process is carried out to increase the octane number of fuel as follows: $C_7H_{14} \rightarrow C_7H_8 + 3H_2$. In this process,two hydrocarbons are in liquid state while $H_2$ is in gaseous state. What is the percentage decrease in the weight of the liquid in the above reaction?

The weight of pure $NaOH$ required to prepare $250 \ cm^3$ of $0.1 \ N$ solution is ......... $g$. (in $g$)