Question

Use the reaction given below to solve the problem that follows: Calculate the mass in grams of aluminum oxide produced by the reaction of 15.0 g of aluminum metal.

[ ]grams Al2O3

4 Al + 3 O2 --> 2 Al2O3

**Your answer should be written as XX.X

Answer 1

Answer:  28.4 g of aluminum oxide is produced by the reaction of 15.0 g of aluminum metal

Explanation:

To calculate the moles :

$\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}$   

$\text{Moles of} Al=\frac{15.0g}{27g/mol}=0.556moles$

The balanced chemical equuation is:

$4Al+3O_2\rightarrow 2Al_2O_3$  

According to stoichiometry :

4 moles of $Al$ produce == 2 moles of $Al_2O_3$

Thus 0.556 moles of $Al$ will produce=$\frac{2}{4}\times 0.556=0.278moles$  of $Al_2O_3$

Mass of $Al_2O_3=moles\times {\text {Molar mass}}=0.278moles\times 102g/mol=28.4g$

Thus 28.4 g of aluminum oxide is produced by the reaction of 15.0 g of aluminum metal.