$X \ g$ of $Ca$ [atomic mass $= 40$] dissolves completely in concentrated $HCl$ solution to produce $5.04 \ L$ of $H_2$ gas at $STP$. The value of $X$ is closest to

How much solid oxalic acid (Molecular weight $126$) has to be weighed to prepare $100 \ mL$ of exactly $0.1 \ N$ oxalic acid solution in water (in $g$)?

The neutralization occurs when $10 \, mL$ of $0.1 \, M$ acid $A$ is allowed to react with $30 \, mL$ of $0.05 \, M$ base $M(OH)_2$. The basicity of the acid $A$ is $...$ $[M$ is a metal$]$

What volume of a solution of hydrochloric acid containing $73 \ g$ of acid per litre would be sufficient for the exact neutralization of sodium hydroxide obtained by allowing $0.46 \ g$ metallic sodium to act upon water? $(Cl = 35.5, Na = 23.0, O = 16, H = 1)$

Write the reaction of aluminum with caustic soda and determine how many moles of $H_2$ gas will be produced at $STP$ from $54 \ g$ of $Al$. (in $mol$)

For preparing one litre $N/10$ solution of $H_2SO_4$,we need $H_2SO_4$.......$g$.