Which of the following is the formula for calcium chlorite?

The molecular mass of an organic compound is $108 \ g \ mol^{-1}$. If $C, H,$ and $N$ atoms are present in the weight ratio of $9 : 1 : 3.5$,what is the molecular formula?

The percentage of oxygen in $NaOH$ is (in $\%$)

Substances $X$ and $Y$ have the same mass. If their atomic weights are $30$ and $20$ respectively,and the molecular weight of the compound is $120$,what is the molecular formula of the compound?

The molecular formula of feldspar is

If the weight percentage of $Se$ (at. wt. $78.4$) in peroxidase anhydrous enzyme is $0.5 \%$,what is the minimum molecular weight of the enzyme?