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

What quantity of ammonium sulphate is necessary for the production of $NH_3$ gas sufficient to neutralize a solution containing $292 \ g$ of $HCl$? $(HCl=36.5, (NH_4)_2SO_4=132, NH_3=17)$

$A$ solution $(5 \, mL)$ of an acid $X$ is completely neutralized by $y \, mL$ of $1 \, M \, NaOH$. The same volume $(y \, mL)$ of $1 \, M \, NaOH$ is required to neutralize $10 \, mL$ of $0.6 \, M \, H_2SO_4$ completely. The normality $(N)$ of the acid $X$ is $......$

In the Victor Meyer method,$0.2 \ g$ of a volatile substance displaces $56 \ mL$ of air at $STP$. The molar mass of the substance is:

To neutralise $20 \, mL$ of $M/10$ sodium hydroxide,the volume of $M/20$ hydrochloric acid required is .............. $mL$

What fraction of $Fe$ exists as $Fe(III)$ in $Fe_{0.96}O$?
(Consider $Fe_{0.96}$ to be made up of $Fe(II)$ and $Fe(III)$ only)