Which is the correct option for $0.1 \ M$,$500 \ mL$ of $AgCl$?

Rearrange the following ($I$ to $IV$) in the order of increasing masses and choose the correct answer (Atomic mass: $N=14, O=16, Cu=63$).
$I.$ $1$ molecule of oxygen
$II.$ $1$ atom of nitrogen
$III.$ $1 \times 10^{-10} \ g$ molecular weight of oxygen
$IV.$ $1 \times 10^{-10} \ g$ atomic weight of copper

$100 \ g$ of a mixture of $NaOH$ and $Na_2SO_4$ is neutralized by $100 \ mL$ of $0.5 \ M \ H_2SO_4$. What is the amount of $Na_2SO_4$ present in the mixture (in $g$)?

When $100 \ mL$ of $1 \ M \ NaOH$ solution and $10 \ mL$ of $10 \ N \ H_2SO_4$ solution are mixed together,the resulting solution will be

Which of the following has the maximum mass?

The density of an equimolar mixture of $CH_4$ and $CO$ at $STP$ is ............... $g \, L^{-1}$.