What is the molar mass of sodium phosphate?

The total of the atomic masses of all atoms in a molecule is the molecule's molecular mass. As a result, if we know the molecular formula, which can be supplied and computed, we can determine the molecular mass.

Sodium phosphate's chemical formula is ${\mathrm{Na}}_3\left({\mathrm{PO}}_4\right)$.

One mole of sodium phosphate has three sodium (Na) atoms, one phosphorus (P) atom, and four oxygen (O) atoms.

Calcium's molar mass is now = 23.0 g/mol

Phosphorus molar mass = 31.0 g/mol

Oxygen atom molar mass= 16.0 g/mol

As a result, the molar mass of ${\mathrm{Na}}_3\left({\mathrm{PO}}_4\right)$is calculated as-

 $\begin{array}{rcl} & & \mathrm{Molar} \mathrm{mass} \mathrm{of} {\mathrm{Na}}_3\left({\mathrm{PO}}_4\right) \\ & =& (3\times 23.0 \mathrm{g}/\mathrm{mol}) + 31.0 \mathrm{g}/\mathrm{mol} + (4\times 16.0 \mathrm{g}/\mathrm{mol})\\ & =& 164.0 \mathrm{g}/\mathrm{mol}\end{array}$

Hence, option A is correct.