the molecular formula of Caffeine is C₈H₁₀N₄O₂
the mass of 1 mol of caffeine - 194 g
In 1 mol of caffeine, mass of C is - 12 x8 = 96 g
Since 1 mol - 194 g, in 194 g of caffeine there's 96 g of Carbon
To find the mass percentage of C
Mass percentage = Mass of Carbon / mass of caffeine x 100%
= 96 g / 194 g x 100
= 49.5 %
49.5 % of caffeine is composed of C.