Will you help me use the half reaction method to balance these equations. I need to add water molecules and hydrogen ions in acid solutions. I also need to keep the balanced equations in net ionic form. thanks

1) Cl-(aq) + NO3-(aq) --> ClO-(aq) +NO(g)
(in acid solution)

2) IO3-(aq) + Br-(aq) --> Br2(l) + IBr(s)
(in acid solution)

3) I2(s) + Na2SO3(aq) --> Na2S2O4(aq) + NaI (aq)
(in acid solution)
Thanks Again clo

1 answer

Here is how you do one of the half reactions.
Let's take NO3^- --> NO

1. Oxidation state N on left is +5; on right is +2
2. Add electrons on appropriate side to balance change of oxidation state.
NO3^- + 3e ==> NO

3. Count charge on left and right. I see -4 on left and zero on right so add H^+ to balance the charge.
NO3^- + 3e + 4H^+ ==> NO

4. Now add H2O to balance the the H+.
NO3^- + 3e + 4H^+ ==> NO + 2H2O

5. Check it.
a. atoms.
N--1 left and right
O--3 on left and 3 right
H -- 4 left and right
b. charge
zero left and right
c. change in oxidation state.
+5 + 3e = +2
Balanced.
If you have follow up questions, show what you've done and explain what you don't understand about the next step.