One mole of which of these compounds contains two moles of hydrogen atoms?

• A. CH4
• B. NH3
• C. H2O
• D. C2H6

Answer: (C)

Verified step by step guidance

1. Identify the number of hydrogen atoms in one molecule of each compound: For CH4, there are 4 hydrogen atoms; for NH3, there are 3 hydrogen atoms; for H2O, there are 2 hydrogen atoms; and for C2H6, there are 6 hydrogen atoms.
2. Recall that one mole of any substance contains Avogadro's number of molecules (approximately \$6.022 \times 10^{23}$ molecules).
3. Calculate the total number of moles of hydrogen atoms in one mole of each compound by multiplying the number of hydrogen atoms per molecule by one mole: For example, for H2O, 1 mole of molecules \(\times\) 2 hydrogen atoms per molecule = 2 moles of hydrogen atoms.
4. Compare the results for each compound to determine which one contains exactly 2 moles of hydrogen atoms per mole of compound.
5. Conclude that the compound with 2 hydrogen atoms per molecule will have 2 moles of hydrogen atoms in one mole of the compound, which matches the correct answer.