A hydrocarbon has a molar mass of 220 g/mol and contains 60% carbon atoms by mass. What is the mass percentage of hydrogen atoms?
Q1. A hydrocarbon has a molar mass of 220 g/mol and contains 60% carbon atoms by mass. What is the mass percentage of hydrogen atoms?
Answer: 17%
Explanation: Atomic mass of C is 12; hence 60/12 = 5 moles of C per mole of compound. Mass of 5 moles of C is 60g, leaving 160g for H (220-60g). Hence, %H = (160g / 220g) * 100 = 72.73%. Option C is the closest due to rounding.