Caffeine has the molecular formula C8H10N4O2. To determine the percent composition of carbon, hydrogen, and nitrogen in a 10 gram sample of caffeine, we first need to find the molar mass of caffeine and then the mass of each element in the sample.1. Calculate the molar mass of caffeine:C: 8 atoms 12.01 g/mol = 96.08 g/molH: 10 atoms 1.01 g/mol = 10.10 g/molN: 4 atoms 14.01 g/mol = 56.04 g/molO: 2 atoms 16.00 g/mol = 32.00 g/molTotal molar mass of caffeine = 96.08 + 10.10 + 56.04 + 32.00 = 194.22 g/mol2. Calculate the mass of each element in the 10 gram sample:Carbon: 96.08 g/mol / 194.22 g/mol 10 g = 4.94 gHydrogen: 10.10 g/mol / 194.22 g/mol 10 g = 0.52 gNitrogen: 56.04 g/mol / 194.22 g/mol 10 g = 2.88 g3. Calculate the percent composition of each element:Carbon: 4.94 g / 10 g 100% = 49.4%Hydrogen: 0.52 g / 10 g 100% = 5.2%Nitrogen: 2.88 g / 10 g 100% = 28.8%So, the percent composition of carbon, hydrogen, and nitrogen in a 10 gram sample of caffeine is approximately 49.4% carbon, 5.2% hydrogen, and 28.8% nitrogen.