Question

Considering the following equation, what is the number of moles of oxygen gas needed to react with 4.00 mol of Mg is ___________.

2Mg + O2 --> 2MgO

2.0 mol

1.0 mol

6.0 mol

3.0 mol

Answer 1

Answer: 2moles

Explanation: 2Mg + O2 --> 2MgO

From the equation, 2 moles of Mg required 1mole of O2.

4 moles of Mg will require Xmole of O2. i.e

Xmol of O2 = 4/2 = 2moles

Therefore, 4moles of Mg requires 2moles of O2