The formula for Cortisone is C₂₁H₂₈O₅.
The molar mass (mass of one molecule) would be the sum of the atomic mass of all the elements that make up Cortisone
∴ mass of one molecule of Cortisone = [(12.01 × 21) + (1.00 × 28) + (15.999 × 5)]g/mol
= (252.21 + 28 + 79.995)
≈ 360 g/mol
That value is due to rounding off. The known accurate value is 360.45 g/mol