When 10 ml mixture of N₂, CO₂ and CO with mole %, 30 %, 40 % and 30 % respectively is combusted in Eudiometer tube and when resulting mixture is pass through Turpentine oil, contraction of 30 ml is observed and when remaining mixture is pass through KOH solution then contraction of x ml is observed, what is the value of x ?

Represent the union of two sets by Venn diagram for each of the following.

$X=\{x | x$ is a prime number between $80$ and $100\}$

$Y=\{y | y$ is an odd number between $90$ and $100\}$

When $100 \mathrm{mL}$ of an ${\mathrm{O}}_2-{\mathrm{O}}_3$ mixture was passed through turpentine, there was a reduction in volume by $20 \mathrm{mL}$. If $100 \mathrm{mL}$ of such a mixture is heated, what will be the increase in volume (in ml) ?

[Hint: ${\mathrm{O}}_3$ is absorbed by turpentine]

$5.22\times {10}^{-4} \mathrm{mol}$ of a gas containing ${\mathrm{H}}_2, {\mathrm{O}}_2$ and ${\mathrm{N}}_2$ exerted a pressure of $67.4 \mathrm{mm}$ in a certain standard volume. The gas was passed over a hot platinum filament which combined ${\mathrm{H}}_2$ and ${\mathrm{O}}_2$ into ${\mathrm{H}}_2\mathrm{O}$ which was frozen out. When the gas was returned to the same volume, the pressure was $14.3 \mathrm{mm}$. Extra oxygen was added to increase the pressure to $44.3 \mathrm{mm}$. The combustion was repeated, after which the pressure read $32.9 \mathrm{mm}$. What was the mole fraction of ${\mathrm{H}}_2, {\mathrm{O}}_2$ and ${\mathrm{N}}_2$ in the gas sample?

[Hint: $2$ volumes of ${\mathrm{H}}_2$ combine with $1$ volume of ${\mathrm{O}}_2$. In the first combustion, ${\mathrm{H}}_2$ is in excess, while in the second one, ${\mathrm{O}}_2$ is in excess]

Ten millilitres of a gaseous hydrocarbon was burnt completely in $80 \mathrm{mL}$ of ${\mathrm{O}}_2$ at $\mathrm{STP}$. The volume of the remaining gas is $70 \mathrm{mL}$. The volume became $50 \mathrm{mL}$ on treatment with $\mathrm{NaOH}$. The formula of the hydrocarbon is: