$1 \ g$ of sodium hydroxide was treated with $25 \ mL$ of $0.75 \ M \ HCl$ solution. The mass of sodium hydroxide left unreacted is equal to:

$KMnO_4$ reacts with $KI$ in basic medium to form $I_2$ and $MnO_2$. When $250 \ mL$ of $0.1 \ M \ KI$ solution is mixed with $250 \ mL$ of $0.02 \ M \ KMnO_4$ in basic medium,what is the number of moles of $I_2$ formed?

For the reaction,$N_{2(g)} + 3H_{2(g)} \to 2NH_{3(g)}$,identify dihydrogen $(H_2)$ as the limiting reagent in the following reaction mixtures.

Moles of conc. $HNO_3$ required to oxidise one mole of sulphur is :
$S + 6HNO_3 \rightarrow H_2SO_4 + 6NO_2 + 2H_2O$

If $30 \ mL$ of $H_2$ and $20 \ mL$ of $O_2$ react to form water,what is left at the end of the reaction?

$CNG$ is an important transportation fuel. When $100 \, g$ of $CNG$ is mixed with $208 \, g$ of oxygen in vehicles,it leads to the formation of $CO_2$ and $H_2O$ and produces a large quantity of heat during this combustion. The amount of carbon dioxide produced in grams is ...... [nearest integer] [Assume $CNG$ to be methane]