Chemistry oxidation state equations:?

Question

3. Some of the reactions of halogens are shown below. They are all examples of redox reactions. In each case state which element is oxidised and which is reduced, and give the oxidation states before and after the reaction. It says it wants you to put the state numbers under each element etc.

a) 2AgCl = 2Ag + Cl2
b) Cl2 + 2OH- = Cl- + ClO- + H20
c) 2Fe + 3Cl2 = 2FeCl3
d) 3Br2 + 6OH- = BrO3- + 5Br- + 3H2O
e) 2Br- +2H+ + H2SO4 = Br2 + So2 + 2H2O
f) 8I- + 8H+ + H2SO4 - 4I2 + H2S + 4H20
g) 4IO3- = 3IO4- + I-
h) H2 + Cl2 = 2HCL
i) 2F2 + 2H2O = 4HF + O2

Please notice that you will have to look quite hard to see the minus signs!

Thanks for all your help, much appreciated! Please

Answer 1

a)
Oxidised: Cl. [-1 to 0]
Reduced: Ag. [+1 to 0]
b)
Oxidised: Cl. [0 to +1](in ClO-)
Reduced: Cl. [0 to -1](in Cl-)
c)
Oxidised: Fe [0 to +3]
Reduced: Cl [0 to -1]
d)
Oxidised: Br. [0 to +5](in BrO3-)
Reduced: Br. [0 to -1](in Br-)
e)
Oxidised: Br. [-1 to 0]
Reduced: S [+6 to +4]
f)
Oxidised: I [-1 to 0]
Reduced: S [+6 to +2](in H2S)
g)
Oxidised: I. [+5 to +7]
Reduced: I. [+5 to -1]
h)
Oxidised: H [0 to +1]
Reduced: Cl. [0 to -1]
i)
Oxidised: O [-2 to 0]
Reduced: F [0 to -1]

Hope this helps=)

Answer 2

they are not hard you should calculate the oxidation number for each element before and after and the one which loose electrons will be oxidized and the one which will gain electron will be reduced.in part a) 2AgCl----> 2Ag +Cl2
here Cl will be oxidized nd Ag will be reduced

Answer 3

CHOOH is formic acid, more commonly written HCOOH H = +1, O = -2 which leaves C as +2