One atomic mass unit $(amu)$ is equal to:

The mass of one molecule of the compound $C_6H_{12}O_6$ is .........

Naturally occurring boron consists of two isotopes with atomic masses $10.01 \ (I)$ and $11.01 \ (II)$. The average atomic mass of natural boron is $10.81$. Find the percentage abundance of isotopes $(I)$ and $(II)$ respectively.

$NaOH + H_3PO_4 \to NaH_2PO_4 + H_2O$; What is the equivalent weight of phosphoric acid in this reaction?

Suppose two elements $X$ and $Y$ combine to form two compounds $XY_{2}$ and $X_{2}Y_{3}$. If $0.05 \ mol$ of $XY_{2}$ weighs $5 \ g$ while $3.011 \times 10^{23}$ molecules of $X_{2}Y_{3}$ weighs $85 \ g$,then atomic masses of $X$ and $Y$ are respectively :

The equivalent mass of an element is $4$ and the vapor density of its chloride is $59.25$. Find the valency of the element.