If $0.2 \ mol$ of sulphuric acid is poured into $250 \ mL$ of water,calculate the concentration of the solution?

What volume of ammonia is required to react with $250 \ mL$ of oxygen by following the reaction at same conditions?
$4NH_3(g) + 5O_2(g) \to 4NO(g) + 6H_2O(g)$

Given $C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O : \Delta H = -72 \ \text{kcal}$,calculate the energy required for the formation of $1.6 \ \text{g}$ of glucose.

The density of $2 \ M$ aqueous solution of $NaOH$ is $1.28 \ g \ cm^{-3}.$ The molality of the solution is $... \ m$ [Given that molecular mass of $NaOH = 40 \ g \ mol^{-1}$]

Galena (an ore) is partially oxidized by passing air through it at high temperature. After some time,the passage of air is stopped,but the heating is continued in a closed furnace such that the contents undergo self-reduction. The weight (in $kg$) of $Pb$ produced per $kg$ of $O_2$ consumed is $. . . . .$ (Atomic weights in $g \ mol^{-1}: O = 16, S = 32, Pb = 207$)

What is $\Delta n$ for the combustion of $1 \ mole$ of benzene,when both the reactants and the products are in the gaseous state at $298 \ K$?