A. 6.02 × 10²³ atoms of hydrogen
B. 4 g-atom of hydrogen
C. 3.0 g of carbon
D. 1.81 × 10²³ molecules of CH?
Correct Answer: B. 4 g-atom of hydrogen
Explanation - Methane (CH?) is a molecule made up of one carbon atom and four hydrogen atoms. When we talk about 1 mole of methane, it means 6.022 × 10²³ molecules of CH?, according to Avogadro’s number.
Since each methane molecule has 4 hydrogen atoms, one mole of methane will contain 4 moles of hydrogen atoms.
The atomic mass of hydrogen is 1 g per mole, so 4 moles of hydrogen atoms correspond to 4 g-atoms of hydrogen.
Important Points
1 mole CH? = 6.022 × 10²³ molecules of methane
Each molecule contains 4 hydrogen atoms
Total hydrogen atoms = 4 × Avogadro’s number
Therefore, hydrogen present = 4 g-atoms
Hence, the correct option is 4 g-atom of hydrogen.