Question

what is the % yield if 4 moles of hydrogen is reacted with 3 moles of oxygen and produces 3 moles of water?
$2h_2 + o_2 \
ightarrow 2h_2o$
\\(\circ\\) 25%
\\(\circ\\) 50%
\\(\circ\\) 100%
\\(\circ\\) 75%

Explanation:

Step1: Find theoretical yield

From the reaction $2H_2 + O_2
ightarrow 2H_2O$, 2 moles $H_2$ produce 2 moles $H_2O$. So 4 moles $H_2$ would theoretically produce $\frac{4}{2} \times 2 = 4$ moles $H_2O$.

Step2: Calculate percent yield

Use formula $\text{Percent Yield} = \frac{\text{Actual Yield}}{\text{Theoretical Yield}} \times 100\%$
Substitute values: $\frac{3}{4} \times 100\% = 75\%$

Answer:

75%