If an element with a mass of $13.8 \, g$ contains $4.6 \times 10^{22}$ atoms,then the atomic mass of the element will be ..............

Equivalent weight of crystalline oxalic acid is ...........

Which one of the following properties of an element is not variable?

Elements $A$ and $B$ form two compounds $B_2A_3$ and $B_2A$. $0.05$ moles of $B_2A_3$ weigh $9.0 \ g$ and $0.10$ mole of $B_2A$ weigh $10 \ g$. The atomic weights of $A$ and $B$ are:

In the reaction $Ca(OH)_2 + H_3PO_4 \to CaHPO_4 + 2H_2O$,the equivalent weight of $H_3PO_4$ is:

The mass of one mole of a substance in grams is called ....... .