In the reaction 2H_2 + O_2 ightarrow 2H_2O, how many moles of hydrogen gas (H_2) are required to react completely with 6.28 mol of oxygen gas (O_2)?

• A. 6.28 mol
• B. 2.00 mol
• C. 3.14 mol
• D. 12.6 mol

Answer: (D)

Verified step by step guidance

1. Identify the balanced chemical equation: \$2H_2 + O_2 \rightarrow 2H_2O$.
2. From the balanced equation, note the mole ratio between hydrogen gas (\(H_2\)) and oxygen gas (\(O_2\)). It is \$2\( moles of \)H_2\( for every \)1\( mole of \)O_2$.
3. Given the amount of oxygen gas is \$6.28\( moles, use the mole ratio to find the moles of hydrogen gas required: multiply \)6.28\( moles of \)O_2\( by the ratio \)\frac{2 \text{ moles } H_2}{1 \text{ mole } O_2}$.
4. Set up the calculation as: \$6.28 \text{ mol } O_2 \times \frac{2 \text{ mol } H_2}{1 \text{ mol } O_2}$.
5. Perform the multiplication to find the moles of \(H_2\) needed to react completely with \$6.28\( moles of \)O_2$.