Question

Cortisone is a molecular substance containing 21 atoms of carbon per molecule. The mass percentage of carbon in cortisone is 69.98%. Its molar mass is :

• A. 176.5
• B. 252.2
• C. 287.6
• D. 360.1

Answer 1

Answer: (D)

360.1

Answer 2

(4)

% of C =$\frac{massofC}{molarmass}$ ×100

69.98 = $\frac{12 \times 12}{M}$ × 100

M = 360.1.