1. Balance the equation, then answer the following based on the equation
Al + O2 → Al2O3
b. How many moles of aluminum are needed to form 3.7 mol Al2O3?

c. How many moles of oxygen are required to react completely with 14.8 mole Al?

Q1. a) 4Al + 3O₂ ➟ 2Al₂O₃

b) 7.4 moles

c) 11.1 moles

Explanation:

To balance an equation, ensure that the total number of atoms of each element on both sides are equal.

Al + O₂ ➟ Al₂O₃

On the left side of the arrow, you would find the reactants while the product(s) is found on the left hand side.

Reactants

Al atoms: 1

O atoms: 2

Product

Al atoms: 2

O atoms: 3

After balancing,

4Al + 3O₂ ➟ 2Al₂O₃

We have 4 Al atoms and 6 O atoms on both sides.

b) The balanced equation tells us the mole ratio of Al to Al₂O₃.

Al: Al₂O₃

= 4: 2 (÷2 throughout)

= 2: 1

This means that for every 1 mole of Al₂O₃, 2 moles of Al is needed.

Since we need 3.7 moles of Al₂O₃,

number of moles of Al needed

= 2×3.7

= 7.4

c) 4Al + 3O₂ ➟ 2Al₂O₃

For every 4 moles of Al, 3 moles of O are needed.

For each mole of Al,

number of moles of O needed

= 3÷4

= 0.75

For 14.8 moles of Al,

number of moles of O required

= 0.75 ×14.8

= 11.1