Question Detail
Question
What is the mass percent composition of nitrogen in adenosine triphosphate (C₁₀H₁₆N₅P₃O₁₃)?
Correct Answer
Option B is the correct answer.
Detailed Explanation
Molar mass of ATP = (10×12.01) + (16×1.008) + (5×14.01) + (3×30.97) + (13×16.00) = 120.1 + 16.128 + 70.05 + 92.91 + 208 = 507.188 g/mol. Mass of N = 5 × 14.01 = 70.05 g/mol. (70.05 / 507.188) × 100% = 13.81%.
Hint
Calculate the total molar mass first, then the mass contribution of all nitrogen atoms.