Caffeine is an alkaloid with the molecular formula C8H10N4O2. To determine the percentage composition of nitrogen N , carbon C , and hydrogen H in caffeine, we will first need to calculate the molar mass of caffeine and then the mass percentage of each element.1. Calculate the molar mass of caffeine:C: 12.01 g/mol 8 atoms = 96.08 g/molH: 1.01 g/mol 10 atoms = 10.10 g/molN: 14.01 g/mol 4 atoms = 56.04 g/molO: 16.00 g/mol 2 atoms = 32.00 g/molTotal molar mass of caffeine = 96.08 + 10.10 + 56.04 + 32.00 = 194.22 g/mol2. Calculate the mass percentage of each element:Carbon C : 96.08 g/mol / 194.22 g/mol 100% = 49.48%Hydrogen H : 10.10 g/mol / 194.22 g/mol 100% = 5.20%Nitrogen N : 56.04 g/mol / 194.22 g/mol 100% = 28.85%So, the percentage composition of the caffeine sample obtained from coffee beans is approximately 49.48% carbon, 5.20% hydrogen, and 28.85% nitrogen.