Question

in the reaction represented by the equation 2al₂o₃→4al + 3o₂, what is the mole ratio of aluminum to oxygen?
4:3
3:4
2:3
4
multiple choice 1 point
in the equation 2kclo₃→2kcl + 3o₂, how many moles of oxygen are produced when 3.0 mol of kclo₃ decompose completely?
4.5 mol
2.5 mol
3.0 mol

Explanation:

First Question

Step1: Identify mole ratios from equation

In the equation \(2Al_2O_3
ightarrow4Al + 3O_2\), the coefficients of \(Al\) is \(4\) and of \(O_2\) is \(3\).

Step2: Write mole ratio

The mole ratio of \(Al\) to \(O_2\) is \(4:3\) (since mole ratio is based on coefficients in balanced chemical equation).

Step1: Set up proportion from equation

From \(2KClO_3
ightarrow2KCl + 3O_2\), the ratio of \(KClO_3\) to \(O_2\) is \(2:3\). Let \(x\) be moles of \(O_2\). So \(\frac{2}{3}=\frac{3.0}{x}\).

Step2: Solve for \(x\)

Cross - multiply: \(2x = 3\times3.0\), then \(x=\frac{9.0}{2}=4.5\) mol.

Answer:

\(4:3\)

Second Question