If isobutane and $n$-butane are present in a gas,then how much oxygen should be required for complete combustion of $10 \ kg$ of this gas? (in $kg$)

The volume of $0.05 \, M$ $H_2SO_4$ required to neutralize $80 \, mL$ of $0.13 \, N$ $NaOH$ will be ...... $mL$.

$23 \ g$ of $Na$ will react with methyl alcohol to give:

When $17 \ g$ of $H_2A$ (dibasic acid) is completely neutralized with $100 \ mL$ of $1 \ M \ BOH$ (monoacidic base),the molecular weight of the acid is:

Phosphoric acid $(H_3PO_4)$ is a tribasic acid,and one of its salts is sodium dihydrogen phosphate $(NaH_2PO_4)$. What volume of $1 \, M \, NaOH$ solution (in $mL$) must be added to $12 \, g$ of sodium dihydrogen phosphate (molar mass $= 120 \, g/mol$) to convert it into trisodium phosphate $(Na_3PO_4)$?

$25 \ cm^3$ of oxalic acid completely neutralized $0.064 \ g$ of sodium hydroxide. The molarity of the oxalic acid solution is: (in $M$)