a. How many moles of aluminum oxide will be formed from 17 moles of aluminum reacting? b. How many moles of oxygen are needed to react with 23.8 moles of aluminum?

Steps to Solve

1. Write the Balanced Chemical Equation

   The reaction between aluminum and oxygen to form aluminum oxide can be written as: $$ 4 \text{Al} + 3 \text{O}_2 \rightarrow 2 \text{Al}_2\text{O}_3 $$

2. Determine Moles of Aluminum Oxide Formed

   From the balanced equation, we see that 4 moles of Al produce 2 moles of ( \text{Al}_2\text{O}_3 ).

   To find the moles of aluminum oxide from 17 moles of aluminum: [ \text{Moles of } \text{Al}_2\text{O}_3 = \frac{2}{4} \times \text{Moles of Al} = \frac{2}{4} \times 17 = \frac{1}{2} \times 17 = 8.5 \text{ moles} ]

3. Calculate Moles of Oxygen Needed

   From the balanced equation, 4 moles of Al require 3 moles of ( \text{O}_2 ).

   To find the moles of oxygen needed for 23.8 moles of aluminum: [ \text{Moles of } \text{O}_2 = \frac{3}{4} \times \text{Moles of Al} = \frac{3}{4} \times 23.8 = \frac{3 \times 23.8}{4} = 17.85 \text{ moles} ]