On a separate sheet of paper, write the formulas for each of the following, complete and balance
1. iron + copper(ii) sulfate
2. potassium chloride + mercury(i) sulfate
3. sulfur + oxygen

The answer to your question is below

Explanation:

1. iron + copper(II) sulfate    ⇒ Iron sulfate + copper

                     Fe + CuSO₄  ⇒   FeSO₄   +  Cu

This is a single replacement reaction

2. potassium chloride + mercury(I) sulfate    ⇒   potassium sulfate + mercury (I) chloride

                    2KCl  +  Hg₂SO₄  ⇒   K₂SO₄  +  2HgCl

This is a double replacement reaction

3. Sulfur + oxygen   ⇒  sulfur dioxide

                     S   +   O₂   ⇒    SO₂

This is a synthesis reaction

Now, all the reactions are balanced.

The first reaction is a single replacement reaction

Fe + CuSO4 => FeSO4 + Cu

Note the charges are indicated in the chemical reaction. SO4 is -2, so Fe is 2+ same with copper

2. Is a double replacement reaction

KCl + Hg2SO4 => K2SO4 + HgCl

Balance then chemical reaction

2 KCl + Hg2SO4 => K2SO4 + 2HgCl

K has a +1 oxidation, Cl is -1, Hg is +1, SO4 has a -2 oxidation

3. Is a synthesis reaction

S + O2 => SO2

Explanation:

what are the choices?