To determine which of the given gases is the heaviest, we need to compare their molar masses, which are the masses of one mole of each gas in grams.
1. Oxygen (O₂)
- Each oxygen atom has an atomic mass of approximately 16 grams per mole.
- Since oxygen gas (O₂) consists of two oxygen atoms, the molar mass of O₂ is:
[tex]\[
2 \times 16 = 32 \text{ grams per mole}
\][/tex]
2. Methane (CH₄)
- Methane consists of one carbon atom and four hydrogen atoms.
- The atomic mass of carbon is approximately 12 grams per mole.
- The atomic mass of hydrogen is approximately 1 gram per mole.
- Therefore, the molar mass of CH₄ is:
[tex]\[
12 + (4 \times 1) = 12 + 4 = 16 \text{ grams per mole}
\][/tex]
3. Carbon Dioxide (CO₂)
- Carbon dioxide consists of one carbon atom and two oxygen atoms.
- The atomic mass of carbon is 12 grams per mole.
- The atomic mass of each oxygen atom is 16 grams per mole.
- Therefore, the molar mass of CO₂ is:
[tex]\[
12 + (2 \times 16) = 12 + 32 = 44 \text{ grams per mole}
\][/tex]
4. Chlorine (Cl₂)
- Chlorine gas (Cl₂) consists of two chlorine atoms.
- The atomic mass of each chlorine atom is approximately 35.5 grams per mole.
- Therefore, the molar mass of Cl₂ is:
[tex]\[
2 \times 35.5 = 71 \text{ grams per mole}
\][/tex]
After calculating the molar masses, we compare them:
- O₂: 32 grams per mole
- CH₄: 16 grams per mole
- CO₂: 44 grams per mole
- Cl₂: 71 grams per mole
Among these values, the heaviest gas is Cl₂ with a molar mass of 71 grams per mole.
Therefore, the heaviest gas is Cl₂.
