Question

Write the formula and calculate the molar mass of magnesium phosphate.

Answer 1

We have to remember that the magnesium phosphates are chemical compounds referred to as sails of magnesium and phosphate which exist in different forms and hydrates. Magnesium phosphate are found in general, in three forms, namely as,
Monomagnesium phosphate $(Mg{({H_2}P{O_4})_2}).{H_2}O$
Dimagnesium phosphate $(MgHP{O_4}).{H_2}O$
Trimagnesium phosphate $(M{g_3}{(P{O_4})_2}).{H_2}O$
The water compound in the above chemical representation is called as water of crystallization. Here, in this particular question we are referring to Trimagnesium phosphate.

Complete step by step answer:
-We have to know that the magnesium phosphate is generally represented by the chemical formula – $M{g_3}{(P{O_4})_2}$.
Since, we have the chemical formula so we can determine the molar mass of the compound.
-We know the different molar mass of the elements present in the chemical formula.
Hence, we have
$Mg = 24{\text{g/mol}}$
$P = 31{\text{g/mol}}$
$O = 16{\text{g/mol}}$
-Based on chemical formula we have 3 moles of magnesium, 2 moles of phosphorus and 8 moles of oxygen.
Thus, we have
$3 \times Mg = 72$
$2 \times P = 62$
$8 \times O = 128$
-To find the total molar mass we will sum up together.
$\therefore 3Mg + 2P + 8O$
${\text{ = 72 + 62 + 128}}$
${\text{ = 262}}$
Hence, the molar mass of the compound Magnesium phosphate is $262{\text{g/mol}}$.

Note: We have to remember that the mole is the smallest unit of an element. It is the measure of an amount of substance in its one unit which represents all the properties of that element. The mole of every substance is different. For many it is exactly double to the number of electrons present in that particular atom. But in certain cases, it is not so. Magnesium phosphate exists in three forms, but the mostly stable and organically found form is Magnesium triphosphate. Molar can be obtained using various practical lab experimentations as well. But the most convenient way is to write the chemical formula and then evaluate.