how many moles of oxygen are produced when 8 moles of al are produced?

Answer:

6

Explanation:

Step1: Write the chemical equation

$2Al_2O_3\xrightarrow{electrolysis}4Al + 3O_2$

Step2: Determine mole - ratio

The mole - ratio of $Al$ to $O_2$ is $4:3$.

Step3: Set up proportion

Let $x$ be the moles of $O_2$. We have $\frac{4}{3}=\frac{8}{x}$.

Step4: Solve for $x$

Cross - multiply: $4x = 3\times8$, so $x=\frac{3\times8}{4}=6$.