Zn + VO3 ^- --> Zn ^2+ + V^+3

Fe ^2+ + H2O2 + OH- --> Fe (OH) 3
V2O5 + I- + H^+ --> VO2 + I2 + H20
P + H+ + NO3- + H2O -->'NO + H3PO4

Like redox reactions

All you will ever need to know about redox and balancing.

http://www.chemteam.info/Redox/Redox.html

To balance these chemical equations, you need to make sure that the number of atoms of each element on both sides of the equation is the same. Here's how you can balance them step by step:

1. Zn + VO3^- → Zn^2+ + V^+3

To balance this equation, start by balancing the elements that appear in more than one compound. In this case, there is only one zinc (Zn) on the left side, so we can start by balancing it:

Zn + VO3^- → Zn^2+ + V^+3

Next, we can balance the vanadium (V) by adding a coefficient of 3 in front of the VO3^- on the left side:

Zn + 3VO3^- → Zn^2+ + V^+3

Now, let's balance the oxygen (O) atoms by adding water (H2O) molecules:

Zn + 3VO3^- → Zn^2+ + V^+3 + 3H2O

Finally, let's balance the charges by adding electrons (e^-):

Zn + 3VO3^- + 4e^- → Zn^2+ + V^+3 + 3H2O

The balanced equation is:

Zn + 3VO3^- + 4e^- → Zn^2+ + V^+3 + 3H2O

2. Fe^2+ + H2O2 + OH^- → Fe(OH)3

Start by balancing the iron (Fe) atoms:

Fe^2+ + H2O2 + OH^- → Fe(OH)3

Next, balance the hydrogen (H) atoms by adding H2O on the right side:

Fe^2+ + H2O2 + OH^- → Fe(OH)3 + H2O

Now, let's balance the oxygen (O) atoms by adding water (H2O) molecules:

Fe^2+ + H2O2 + OH^- → Fe(OH)3 + H2O

Finally, let's balance the charges by adding electrons (e^-):

Fe^2+ + H2O2 + OH^- + 3e^- → Fe(OH)3 + H2O

The balanced equation is:

Fe^2+ + H2O2 + OH^- + 3e^- → Fe(OH)3 + H2O

3. V2O5 + I^- + H^+ → VO2 + I2 + H2O

Start by balancing the iodine (I) atoms by adding a coefficient of 2 in front of I2 on the right side:

V2O5 + I^- + H^+ → VO2 + 2I2 + H2O

Next, balance the hydrogen (H) atoms by adding H2O on the right side:

V2O5 + I^- + H^+ → VO2 + 2I2 + H2O

Finally, let's balance the charges by adding electrons (e^-):

V2O5 + I^- + H^+ + 2e^- → VO2 + 2I2 + H2O

The balanced equation is:

V2O5 + I^- + H^+ + 2e^- → VO2 + 2I2 + H2O

4. P + H^+ + NO3^- + H2O → NO + H3PO4

Start by balancing the phosphorus (P) atoms. There's only one P on the left side, so we can start by balancing it:

P + H^+ + NO3^- + H2O → NO + H3PO4

Next, balance the hydrogen (H) atoms by adding H2O on the left side:

P + H^+ + NO3^- + 4H2O → NO + H3PO4

Now, balance the oxygen (O) atoms by adding H2O on the right side:

P + H^+ + NO3^- + 4H2O → NO + H3PO4 + 4H2O

Finally, let's balance the charges by adding electrons (e^-):

P + H^+ + NO3^- + 4H2O + 8e^- → NO + H3PO4 + 4H2O

The balanced equation is:

P + H^+ + NO3^- + 4H2O + 8e^- → NO + H3PO4 + 4H2O