The molecular weight of a gas is $45$. Its density at $STP$ is

What is the mass of potassium chloride produced when $12.25 \ g$ of potassium chlorate undergoes decomposition (in $g$)? (Atomic masses: $K=39, Cl=35.5, O=16$)

Find the quantity of dihydrogen required to prepare $2 \ L$ ammonia gas from $1 \ L$ dinitrogen.

Excess of carbon dioxide is passed through $50 \ mL$ of $0.5 \ M$ calcium hydroxide solution. After the completion of the reaction,the solution was evaporated to dryness. The solid calcium carbonate was completely neutralized with $0.1 \ N$ hydrochloric acid. The volume of hydrochloric acid required is (Atomic mass of calcium $= 40$ ) (in $cm^{3}$)

To change the strength of $25 \, mL$ of $0.15 \, M$ $HCl$ to $0.1 \, M$,the quantity of water that is to be added is.......$mL$

$A$ container contains $4 \ g$ of $H_2$,$4 \ g$ of $He$,and a certain amount of $Ne$ at a certain temperature. What is the mass of $Ne$ required so that the partial pressure exerted by $Ne$ is equal to the partial pressure of $He$ (in $g$)?