Number of moles of methane required to produce $22 \ g$ $CO_{2(g)}$ after combustion is $x \times 10^{-2}$ moles. The value of $x$ is

Ferrous sulphate heptahydrate is used to fortify foods with iron. The amount (in $grams$) of the salt required to achieve $10 \; ppm$ of iron in $100 \; kg$ of wheat is
Atomic weight : $Fe = 55.85$,$S = 32.0$,$O = 16.00$

How much water is needed to dilute $10 \, mL$ of $10 \, N$ hydrochloric acid to make it exactly decinormal $(0.1 \, N)$? .......... $mL$

Dissolving $1.24 \ g$ of white phosphorus in boiling $NaOH$ solution in an inert atmosphere gives a gas $Q$. The amount of $CuSO_4$ (in $g$) required to completely consume the gas $Q$ is. . . . [Given: Atomic mass of $H = 1, O = 16, Na = 23, P = 31, S = 32, Cu = 63$]

$10 \ mL$ of a gaseous hydrocarbon on combustion gives $40 \ mL$ of $CO_{2(g)}$ and $50 \ mL$ of water vapour. The total number of carbon and hydrogen atoms in the hydrocarbon is:

The molarity of a $NaOH$ solution prepared by dissolving $4 \ g$ of it in $250 \ mL$ of water is: (in $M$)