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 0.770 mol of magnesium burns?

Answer 1

0.385 moles O2 are consumed when 0.770 moles magnesium burns

Step-by-step explanation:

Step 1: Data given

Number of moles of magnesium = 0.770 moles

Step 2: The balanced equation

2Mg(s) + O2(g) → 2MgO(s)

For 2 moles Mg we need 1 mol O2 to produce 2 moles MgO

For 0.770 moles Mg we need 0.770/2 = 0.385 moles O2

0.385 moles O2 are consumed when 0.770 moles magnesium burns

Answer 2

The answer to your question is 0.385 moles of O₂

Step-by-step explanation:

Data

moles of O₂ = ?

moles of Mg = 0.77

Balanced chemical reaction

2Mg(s) + O₂(g) ⇒ 2MgO (s)

Process

1.- To solve this problem, just use the coefficients of the balanced reaction.

2 moles of Mg ---------------- 1 mol of O₂

0.770 moles of Mg ------------- x

x = (0.770 moles of Mg x 1 mol of O₂) / 2 moles of Mg

x = 0.770 / 2

- Result

x = 0.385 moles of O₂