Comparing Mass: Oxygen vs Methane at STP
How do I determine the mass that has the same mass 11.2 L of O₂ at STP?
Which of the following volumes of Methane, CH₄ at STP, has the same mass as 11.2 L of O₂ at STP?
1) 11.2 L of Methane at STP
2) 22.4 L of Methane at STP
3) 33.6 L of Methane at STP
4) 44.8 L of Methane at STP
Answer:
To determine the mass that has the same mass as 11.2 L of O₂ at STP, we need to compare the mass of oxygen to different volumes of methane at STP.
First, let's find the mass of 11.2 L of O₂ at STP:
Volume of O₂ = 11.2 L
Mole of O₂ = 11.2 L / 22.4 L = 0.5 mole
Molar mass of O₂ = 32 g/mol
Mass of O₂ = 0.5 mole × 32 g/mol = 16 grams
Now, let's calculate the mass of different volumes of methane:
For 11.2 L of Methane, CH₄:
Mole of CH₄ = 11.2 L / 22.4 L = 0.5 mole
Mass of CH₄ = 0.5 mole × 16 g/mol = 8 grams
For 22.4 L of Methane, CH₄:
Mole of CH₄ = 22.4 L / 22.4 L = 1 mole
Mass of CH₄ = 1 mole × 16 g/mol = 16 grams
For 33.6 L of Methane, CH₄:
Mole of CH₄ = 33.6 L / 22.4 L = 1.5 moles
Mass of CH₄ = 1.5 moles × 16 g/mol = 24 grams
For 44.8 L of Methane, CH₄:
Mole of CH₄ = 44.8 L / 22.4 L = 2 moles
Mass of CH₄ = 2 moles × 16 g/mol = 32 grams
Therefore, 11.2 L of O₂ at STP has the same mass as 22.4 L of Methane, CH₄ (2nd option).