Question

Magnesium burns in air with a dazzling brilliance to produce magnesium oxide: 2mg(s) + o2(g) → 2mgo(s) how many moles of o2 are consumed when 0.550 mol of magnesium burns?

Answer 1

Answer is: 0,275 moles of oxygen are consumed.
Chemical reaction: 2Mg + O₂ → 2MgO.
n(Mg) = 0,550 mol.
n(O₂) = ?
from chemical reaction: n(Mg) : n(O₂) = 2 : 1.
0,550 mol : n(O₂) = 2 : 1.
2n(O₂) = 0,550 mol.
n(O₂) = 0,275 mol.
n - amount of substance.

Answer 2

Answer: 0.275 moles of oxygen gas is consumed in the reaction.

Explanation:

We are given:

Moles of magnesium = 0.550 moles

For the given chemical reaction:

$2Mg(s)+O_2(g)\rightarrow 2MgO(s)$

By Stoichiometry of the reaction:

2 moles of magnesium reacts with 1 mole of oxygen gas.

So, 0.550 moles of magnesium will react with = $\frac{1}{2}\times 0.550=0.275mol$ of oxygen gas.

Hence, 0.275 moles of oxygen gas is consumed in the reaction.