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

How many moles of ethene are required to prepare $6.0 \ g$ of ethane by the hydrogenation process (in $mole$)?

According to the reaction,$Mg_{(s)} + 2HCl_{(aq)} \longrightarrow MgCl_{2_{(aq)}} + H_{2_{(g)}} \uparrow$,calculate the mass of $Mg$ required to liberate $4.48 \ dm^3$ of $H_2$ gas at $STP$. (Molar mass of $Mg = 24 \ g \ mol^{-1}$) (in $g$)

What volume (in $mL$) of $HCl$ solution containing $73 \ g$ per litre is required to completely neutralise sodium hydroxide solution,obtained by allowing $0.46 \ g$ of metallic sodium to act upon water?

Calculate the molarity $(M)$ of a $H_2SO_4$ solution that has a density of $1.84 \ g/mL$ and is $98 \% \, w/w$.

The normality of orthophosphoric acid having purity of $70\%$ by weight and specific gravity $1.54$ would be ............. $N$.