Question

Calculate the molecular mass of Potassium nitrate $\left({\mathrm{KNO}}_3\right)$

Given Atomic masses: K = 39u, N = 14u, O = 16u

Answer 1

Step 1: Calculating the molecular mass

Molecular mass is equal to the sum of atomic masses of all the atoms present in one molecule of a substance.

Step 2: Given data

Atomic masses: K = 39u, N = 14u, O = 16u

Step 3: Finding the molecular mass for the given data

The molecular mass of $\left({\mathrm{KNO}}_3\right)$ = (Number of potassium atoms x atomic mass of potassium) + (Number of nitrogen atoms x atomic mass of nitrogen) + (Number of oxygen atoms x atomic mass of oxygen)

The molecular mass of $\left({\mathrm{KNO}}_3\right)$ = $\left(1\times 39\right)+\left(1\times 14\right)+\left(3\times 16\right)$

The molecular mass of $\left({\mathrm{KNO}}_3\right)$ = $39+14+48=101$g/mol

Hence, the molecular mass of Potassium nitrate $\left({\mathrm{KNO}}_3\right)$ is $101$g/mol