To determine the number of atoms present in a given amount of a substance, you need to know Avogadro's number, which is approximately 6.022 × 10^23 atoms per mole. In the case of methane (CH4), there is one carbon atom (C) and four hydrogen atoms (H).
To calculate the number of atoms in 5 moles of methane:
Determine the number of moles of carbon: Since each molecule of methane contains one carbon atom, the number of moles of carbon is the same as the number of moles of methane, which is 5 moles.
Determine the number of atoms of carbon: Multiply the number of moles of carbon by Avogadro's number to get the number of carbon atoms: Number of carbon atoms = Number of moles of carbon × Avogadro's number Number of carbon atoms = 5 moles × (6.022 × 10^23 atoms/mole) Number of carbon atoms = 3.011 × 10^24 atoms
Determine the number of moles of hydrogen: Each molecule of methane contains four hydrogen atoms, so the number of moles of hydrogen is four times the number of moles of methane: Number of moles of hydrogen = 5 moles × 4 = 20 moles
Determine the number of atoms of hydrogen: Multiply the number of moles of hydrogen by Avogadro's number to get the number of hydrogen atoms: Number of hydrogen atoms = Number of moles of hydrogen × Avogadro's number Number of hydrogen atoms = 20 moles × (6.022 × 10^23 atoms/mole) Number of hydrogen atoms = 1.2044 × 10^25 atoms
Therefore, in 5 moles of methane, there are approximately 3.011 × 10^24 carbon atoms and 1.2044 × 10^25 hydrogen atoms.