During a synthesis reaction, 2.4 grams of magnesium reacted with 8.0 grams of oxygen. What is the maximum amount of magnesium oxide that can be produced during the reaction?


Mg + O2 → MgO


2.1 grams

2.8 grams

3.6 grams

3.9 grams

Respuesta :

Answer: The maximum amount of magnesium oxide produced during the reaction can be, 3.9 grams.

Explanation : Given,

Mass of [tex]Mg[/tex] = 2.4 g

Mass of [tex]O_2[/tex] = 8.0 g

Molar mass of [tex]Mg[/tex] = 24.3 g/mol

Molar mass of [tex]O_2[/tex] = 31.9 g/mol

First we have to calculate the moles of [tex]Mg[/tex] and [tex]O_2[/tex].

[tex]\text{Moles of }Mg=\frac{\text{Given mass }Mg}{\text{Molar mass }Mg}[/tex]

[tex]\text{Moles of }Mg=\frac{2.4g}{24.3g/mol}=0.099mol[/tex]

and,

[tex]\text{Moles of }O_2=\frac{\text{Given mass }O_2}{\text{Molar mass }O_2}[/tex]

[tex]\text{Moles of }O_2=\frac{8.0g}{31.9g/mol}=0.25mol[/tex]

Now we have to calculate the limiting and excess reagent.

The balanced chemical equation is:

[tex]2Mg+O_2\rightarrow 2MgO[/tex]

From the balanced reaction we conclude that

As, 2 mole of [tex]Mg[/tex] react with 1 mole of [tex]O_2[/tex]

So, 0.099 moles of [tex]Mg[/tex] react with [tex]\frac{0.099}{2}=0.049[/tex] moles of [tex]O_2[/tex]

From this we conclude that, [tex]O_2[/tex] is an excess reagent because the given moles are greater than the required moles and [tex]Mg[/tex] is a limiting reagent and it limits the formation of product.

Now we have to calculate the moles of [tex]MgO[/tex]

From the reaction, we conclude that

As, 2 mole of [tex]Mg[/tex] react to give 2 mole of [tex]MgO[/tex]

So, 0.099 mole of [tex]Mg[/tex] react to give 0.099 mole of [tex]MgO[/tex]

Now we have to calculate the mass of [tex]MgO[/tex]

[tex]\text{ Mass of }MgO=\text{ Moles of }MgO\times \text{ Molar mass of }MgO[/tex]

Molar mass of [tex]MgO[/tex] = 40.3 g/mole

[tex]\text{ Mass of }MgO=(0.099moles)\times (40.3g/mole)=3.9g[/tex]

Therefore, the maximum amount of magnesium oxide produced during the reaction can be, 3.9 grams.