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

$A$ sample of $NaClO_3$ is converted by heat to $NaCl$ with a loss of $0.16 \ g$ of oxygen. The residue is dissolved in water and precipitated as $AgCl$. The mass of $AgCl$ (in $g$) obtained will be (Given: Molar mass of $AgCl = 143.5 \ g \ mol^{-1}$)

$A$ gas mixture contains $25 \%$ He and $75 \% CH_4$ by volume at a given temperature and pressure. The percentage by mass of methane in the mixture is approximately . . . . . . (in $\%$)

At $300 \ K$ and $1 \ atm$,$15 \ mL$ of a gaseous hydrocarbon requires $375 \ mL$ of air containing $20 \% \ O_2$ by volume for complete combustion. After combustion,the gases occupy $330 \ mL$. Assuming that the water formed is in liquid form and the volumes were measured at the same temperature and pressure,the formula of the hydrocarbon is:

$100 \ mL$ of $PH_3$ when completely decomposed produces phosphorus and hydrogen. The change in volume of the gas is
$PH_{3(g)} \longrightarrow P_{(s)} + \frac{3}{2} H_{2(g)}$

The molar mass of $CaCO_{3}$ is $100 \ g/mol$. The maximum amount of carbon dioxide that can be liberated on heating $25 \ g$ of $CaCO_{3}$ is $.... \ g$.