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)

Find the mass of sodium carbonate in grams required to prepare $100 \text{ ml}$ of a $0.1 \text{ M}$ aqueous solution. (Molar mass of $Na_2CO_3 = 106 \text{ g/mol}$) (in $\text{ g}$)

When the same amount of zinc is treated separately with an excess of sulphuric acid and an excess of sodium hydroxide solution,the ratio of the volumes of hydrogen evolved is:

If $0.45 \ g$ of a gas with molecular weight $60$ and $0.22 \ g$ of another gas with molecular weight $44$ are present,and the total pressure exerted by the mixture is $75 \ cm \ Hg$,then the partial pressure of the second gas is .......... $cm$ of $Hg$.

The heat of combustion of methane is given by the following equation. How many grams of methane are required to produce $445 \ kJ$ of heat (in $g$)?
$CH_4 + 2O_2 \rightarrow CO_2 + 2H_2O \ (\Delta H = -891 \ kJ/mol)$

How much water is needed to dilute $10 \, mL$ of $10 \, N$ hydrochloric acid to make it exactly decinormal $(0.1 \, N)$? .......... $mL$