Given the reaction CH4 + 2O2 → CO2 + 2H2O, how many grams of CO2 are produced from 125 g of O2 and excess CH4?

• A. 44.0 g
• B. 86.0 g
• C. 125 g
• D. 62.5 g

Answer: (B)

Verified step by step guidance

1. Write down the balanced chemical equation: \(\mathrm{CH_4 + 2O_2 \rightarrow CO_2 + 2H_2O}\).
2. Identify the given quantity and what is asked: Given 125 g of \(\mathrm{O_2}\) and excess \(\mathrm{CH_4}\), find the mass of \(\mathrm{CO_2}\) produced.
3. Calculate the number of moles of \(\mathrm{O_2}\) using its molar mass: \(\mathrm{moles\ of\ O_2 = \frac{mass\ of\ O_2}{molar\ mass\ of\ O_2}}\), where the molar mass of \(\mathrm{O_2}\) is approximately 32.0 g/mol.
4. Use the mole ratio from the balanced equation to find moles of \(\mathrm{CO_2}\) produced: from the equation, 2 moles of \(\mathrm{O_2}\) produce 1 mole of \(\mathrm{CO_2}\), so \(\mathrm{moles\ of\ CO_2 = \frac{1}{2} \times moles\ of\ O_2}\).
5. Convert moles of \(\mathrm{CO_2}\) to grams using the molar mass of \(\mathrm{CO_2}\) (approximately 44.0 g/mol): \(\mathrm{mass\ of\ CO_2 = moles\ of\ CO_2 \times molar\ mass\ of\ CO_2}\).