$925$ fine silver means an alloy of :

The percentage of nitrogen by mass in ammonium sulphate is closest to $.....$ $\%$ (atomic masses of $H = 1, N = 14, O = 16, S = 32$ ).

$A$ gas is found to have a formula $[CO]_x$. If its vapour density is $70$,the value of $x$ is

Which of the following is the formula for calcium chlorite?

An organic compound contains $69 \%$ carbon and $4.8 \%$ hydrogen,the remainder being oxygen. Calculate the masses of carbon dioxide and water produced when $0.20 \ g$ of this substance is subjected to complete combustion.

Determine the empirical formula of an oxide of iron which has $69.9 \%$ iron and $30.1 \%$ dioxygen by mass.