MDCAT Chemistry MCQ #450

Methanal is the simplest aldehyde. What is the percentage by mass of hydrogen in a single molecule of methanal?

MDCAT Chemistry MCQ #450

  1. Question 1

    Q1. Methanal is the simplest aldehyde. What is the percentage by mass of hydrogen in a single molecule of methanal?

    • A) 3.33%
    • B) 6.67%
    • C) 13.3%
    • D) 20.0%

    Answer: 6.67%

    Explanation: Methanal (CH2O) has a mass of 30, with 2 parts hydrogen; (2/30)*100 equals 6.67%. 3.33% is the hydrogen mass in heavier compounds.