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 .............. $\%$.

Blue vitriol is

Identify the compound formed from elements $X, Y, Z$ having oxidation states $+2, +5, -2$ respectively.

$3.0$ molal $NaOH$ solution has a density of $1.110 \, g/mL$. The molarity of the solution is

The normality of $H_{2}SO_{4}$ in the solution obtained on mixing $100 \ mL$ of $0.1 \ M \ H_{2}SO_{4}$ with $50 \ mL$ of $0.1 \ M \ NaOH$ is $\times 10^{-1} \ N$. (Nearest Integer)

The incorrect postulates of the Dalton's atomic theory are :
$A$. Atoms of different elements differ in mass.
$B$. Matter consists of divisible atoms.
$C$. Compounds are formed when atoms of different element combine in a fixed ratio.
$D$. All the atoms of given element have different properties including mass.
$E$. Chemical reactions involve reorganisation of atoms.
Choose the correct answer from the options given below :