MDCAT Chemistry MCQ #453

A sample of methanal gas weighs exactly 15 grams. What is the total number of atoms present in this specific sample?

MDCAT Chemistry MCQ #453

  1. Question 1

    Q1. A sample of methanal gas weighs exactly 15 grams. What is the total number of atoms present in this specific sample?

    • A) 3.01x10^23
    • B) 6.02x10^23
    • C) 1.20x10^24
    • D) 2.41x10^24

    Answer: 1.20x10^24

    Explanation: Methanal (CH2O) has four atoms; 15g is 0.5 moles, resulting in 2.0 moles of atoms (1.204x10^24). 6.02x10^23 is one mole.