Answer:
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
