How do I do these?

Question

1. Balance the equation for the reaction between zinc and hydrochloric acid.

Zn + HCl ZnCl2 + H2

2. Balance the equation for the reaction between iron (steel wool) and oxygen (water).

Fe + O2 Fe2O3

3. Balance the equation for the reaction of hydrogen peroxide in the presence of catalase.

H2O2 H2O + O2

4. Balance the equations below for the reaction of acetic acid and sodium bicarbonate

NaHCO3 + HC2H3O2 NaC2H3O2 + H2CO3

H2CO3 H2O + CO2

NaHCO3 + HC2H3O2 NaC2H3O2 + H2O + CO2

Answer 1

http://www.dummies.com/education/science/chemistry/how-to-balance-chemical-reactions-in-equations/