The formula of a metallic oxide is $MO$. What will be the formula of its phosphate?

Six volumes of oxygen,on complete ozonisation,form ...... volumes of ozone.

What is the molarity of $H_2SO_4$ solution if $25 \ mL$ is exactly neutralized with $32.63 \ mL$ of $0.164 \ M$ $NaOH$ (in $M$)?

$A$ $20 \ mL$ solution of $KMnO_4$ with a concentration of $1 \ N$ reacts with $20 \ mL$ of oxalic acid. The weight of oxalic acid in the $1 \ N$ solution is ......... $g$.

Galena (an ore) is partially oxidized by passing air through it at high temperature. After some time,the passage of air is stopped,but the heating is continued in a closed furnace such that the contents undergo self-reduction. The weight (in $kg$) of $Pb$ produced per $kg$ of $O_2$ consumed is $. . . . .$ (Atomic weights in $g \ mol^{-1}: O = 16, S = 32, Pb = 207$)

The volume occupied by $4.4 \ g$ of $CO_2$ at $STP$ is ............... $L$.