Question

1. write a balanced chemical equation to represent each reaction described below. (a) aluminum metal reacts with oxygen to form aluminum oxide. (b) metallic zinc combines with sulphur to form zinc sulphide.

Explanation:

Step1: Identify reactants and products for (a)

Aluminum (Al) and oxygen ($O_2$) react to form aluminum oxide ($Al_2O_3$).

Step2: Balance the equation for (a)

We need 4 Al atoms and 3 $O_2$ molecules to get 2 $Al_2O_3$ molecules. So the balanced equation is $4Al + 3O_2=2Al_2O_3$.

Step3: Identify reactants and products for (b)

Zinc (Zn) and sulphur (S) react to form zinc sulphide (ZnS).

Step4: Balance the equation for (b)

1 Zn atom and 1 S atom form 1 ZnS molecule. So the balanced equation is $Zn + S = ZnS$.

Answer:

(a) $4Al + 3O_2=2Al_2O_3$
(b) $Zn + S = ZnS$