Partially dried soil contains $50 \%$ silica and $7 \%$ water. If the original soil contained $12 \%$ water,then the percentage of silica in the original soil is .............. $\%$.

$1 \ g$ equivalent of a substance is present in:

Hydrochloric acid solutions $A$ and $B$ have concentrations of $0.5 \ N$ and $0.1 \ N$ respectively. The volumes of solutions $A$ and $B$ required to make $2 \ L$ of $0.2 \ N$ $HCl$ are:

If the density of liquid water is $1.0 \, g \cdot cm^{-3}$ and the density of water vapor is $0.0006 \, g \cdot cm^{-3}$ at $100 \, ^\circ C$ and $1 \, atm$ pressure,then what is the volume occupied by water molecules in $1 \, L$ of steam at the same temperature in $cm^3$?

In which of the following reactions is no gas evolved on the product side? (Temperature is maintained below the boiling point of liquids formed)

Iron sulphide is heated in air to form $A$,an oxide of sulphur. $A$ is dissolved in water to give an acid. The basicity of this acid is