At $300 \ K$ and $1 \ \text{atm}$ pressure,$10 \ mL$ of a hydrocarbon required $55 \ mL$ of $O_2$ for complete combustion,and $40 \ mL$ of $CO_2$ is formed. The formula of the hydrocarbon is

$A$ solution of $H_2SO_4$ is $31.4 \%$ $H_2SO_4$ by mass and has a density of $1.25 \ g \ mL^{-1}$. The molarity of the $H_2SO_4$ solution is . . . . . . $M$ (nearest integer) [Given molar mass of $H_2SO_4 = 98 \ g \ mol^{-1}$]

How many moles of $H_2O_2$ are required for the decolorization of $1$ mole of $KMnO_4$?

In the petroleum industry,a process is carried out to increase the octane number of fuel as follows: $C_7H_{14} \rightarrow C_7H_8 + 3H_2$. In this process,two hydrocarbons are in liquid state while $H_2$ is in gaseous state. What is the percentage decrease in the weight of the liquid in the above reaction?

To neutralize $10 \, mL$ of $M/5$ $NaOH$,the volume of $M/20$ $HCl$ required is......$mL$.

The $NaNO_3$ weighed out to make $50 \ mL$ of an aqueous solution containing $70.0 \ mg$ $Na^{+}$ per $mL$ is $...... \ g$.
(Rounded off to the nearest integer) [Given : Atomic weight in $g \ mol^{-1}$ - $Na : 23$; $N : 14$; $O : 16$]