A hydrocarbon has a molar mass of 150 g/mol and contains 80% carbon atoms by mass. What is the mass percentage of hydrogen atoms?
Q1. A hydrocarbon has a molar mass of 150 g/mol and contains 80% carbon atoms by mass. What is the mass percentage of hydrogen atoms?
Answer: 12%
Explanation: Atomic mass of C is 12; hence 80/12 = 6.67 moles of C per mole of compound. Mass of 6.67 moles of C is 80g, leaving 70g for H (150-80g). Hence, %H = (70g / 150g) * 100 = 46.67%. Option A is the closest due to rounding.