Question

question 1 (1 point)
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limitproduct5. this reaction is about the following reaction:
o₂ + 2 mg → 2 mgo
1.0 moles of oxygen and 1.8 moles of magnesium are mixed for the reaction. how many moles of magnesium oxide will be produced?
1.8 moles
3.6 moles
0.50 moles
1.0 moles
2.0 moles
2.8 moles

Explanation:

Step1: Determine limiting reactant

From reaction $\ce{O2 + 2Mg -> 2MgO}$, mole ratio of $\ce{O2}$ to $\ce{Mg}$ is $1:2$.
Moles of $\ce{O2} = 1.0$, moles of $\ce{Mg} = 1.8$.
For $\ce{O2}$ to react completely, moles of $\ce{Mg}$ needed: $1.0 \times 2 = 2.0$ mol. But we have only $1.8$ mol $\ce{Mg}$, so $\ce{Mg}$ is limiting.

Step2: Calculate moles of $\ce{MgO}$ from $\ce{Mg}$

Mole ratio of $\ce{Mg}$ to $\ce{MgO}$ is $2:2 = 1:1$.
Moles of $\ce{MgO}$ = moles of $\ce{Mg}$ (limiting) = $1.8$ mol.

Answer:

1.8 moles