What is the weight of oxygen that is required for the complete combustion of $2.8 \ kg$ of ethylene? (in $kg$)

Mass of methane required to produce $22 \ g$ of $CO_2$ after complete combustion is . . . . . . $g.$ (Given Molar mass in $g \ mol^{-1}$: $C=12.0, H=1.0, O=16.0$)

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 $(Na_3PO_4)$?

What volume of dioxygen is required for complete combustion of $2 \, \text{volumes}$ of acetylene gas at $NTP$?

The normality of $2.3 \ M$ $H_2SO_4$ solution is ...... $N$.

If Avogadro's number is $A_0$,the number of sulphur atoms present in $200 \, mL$ of $1 \, N \, H_2SO_4$ is