Chemistry; How Do I Do These?

[ImagineDragons]

How in the hell do I do these?

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

[emeritus]

1
Google the others

[bhg481]

The question is aking you to put an = sign in the right place to make the statement an equation.
eg,

Zn + HCl = ZnCl2 + H2

[Kidas]

Hi
Homework questions?
First one shows the way. On the left side you have the inputs: zinc and hydrochloric acid.
On the right side, the outputs: Zinc chloride and hydrogen gas.
The challenge is to find the right nubers pf atoms that can satisfy each side.
Hydrogen gas (on the right) needs two atoms: H2
So you need two atoms of hydrogen on the left:
Zn + 2HCl = ZnCl2 + H2
The number of atoms on each side of the equation is balanced.

The next one is iron rusting
2Fe + O2 = Fe2O3 doesn't work, because the oxygens do not match on left and right.
So we have to modify it thus:
4Fe + 3O2 = 2Fe2O3 (4 atoms of Fe; 6 of oxygen on each side)
Up to you to solve the rest :)

[bhg481]

Nicely explained Kidas - I'd forgotten to look at balancing the atom numbers.