$A$ $250 \, mL$ solution of $Na_2CO_3$ contains $2.65 \, g$ of $Na_2CO_3$. If $10 \, mL$ of this solution is taken and diluted with distilled water up to $0.1 \, L$,what will be the molarity of the resulting solution (in $, M$)?

The drain cleaner,Drainex contains small bits of aluminum which react with caustic soda to produce dihydrogen. What volume of dihydrogen at $20^{\circ} C$ and $1 \, bar$ will be released when $0.15 \, g$ of aluminum reacts?

The molarity of a $98\%$ by weight solution of $H_2SO_4$ is .......... $M$. The density of the solution at $35^o C$ is $1.84 \ g/cm^3$.

$100 \, mL$ of $0.1 \, N \, HCl$ is neutralized by $0.2 \, N \, NaOH$ solution. After adding $30 \, mL$ of $NaOH$ solution,the neutralization is continued using $0.25 \, N \, KOH$. Calculate the volume of $KOH$ in $mL$ required to complete the neutralization.

$100 \, mL$ of a given $H_2O_2$ sample in water (density $1.08 \, g/mL$) required $5 \, mL$ of $M/25 \, KMnO_4$ in acidic medium for its oxidation. Select the correct statement regarding $H_2O_2$ in the sample:

$5 \, L$ of a gaseous mixture of ethane and propane are burnt to produce total $11 \, L$ of $CO_2$. Volume percent of $C_2H_6$ in the initial mixture is