In: Chemistry
Balance each of the following reations using the half reaction method. Show all work
a. Bi(OH)3(S) + Sn(OH)3-(aq) ---> Sn(OH)62- (aq) + Bi(s) (Basic solution)
b. BrO3-(aq) + Sb3+(aq) ---> Br - (aq) + Sb5+ (aq) (acidic solution)
Thank you for your help!
+3 +2 +4 0
Bi(OH)3(S) +
Sn(OH)3-(aq)
Sn(OH)62- (aq) + Bi(s)
Oxidation half reaction : Sn(OH)3-(aq)
Sn(OH)62- (aq)
Reduction half reaction : Bi(OH)3(S) Bi(s)
Balancing oxidation half reaction
:Sn(OH)3-(aq)
Sn(OH)62- (aq)
Balancing O atoms ( by adding H2O ) :
Sn(OH)3-(aq) +
3H2O
Sn(OH)62- (aq)
Balancing H atoms ( by adding H2O &
OH- ) : Sn(OH)3-(aq) +
3H2O + 3OH-
Sn(OH)62- (aq)+
3H2O
Balancing charge ( by adding electrons) :
Sn(OH)3-(aq) + 3H2O +
3OH-
Sn(OH)62- (aq)+ 3H2O +
2e-
Sn(OH)3-(aq) +
3OH-
Sn(OH)62- (aq) +
2e-
---(1)
Balancing Reduction half reaction :
Bi(OH)3(S) Bi(s)
Balancing O atoms ( by adding H2O ) :
Bi(OH)3(S) Bi(s) +
3H2O
Balancing H atoms ( by adding H2O &
OH- ) : Bi(OH)3(S)
+3H2O Bi(s) +
3H2O + 3OH-
Balancing charge ( by adding electrons) : Bi(OH)3(S)
+3H2O+ 3e-
Bi(s) +
3H2O +
3OH-
Bi(OH)3(S) + 3e- Bi(s) +
3OH-
---(2)
Adding both the equations so that the number of electrons must be balanced on both sides.It can be done as follows:
[3xEqn(1) ] + [2xEqn (2)] gives
3Sn(OH)3-(aq) + 9OH-+
2Bi(OH)3(S) + 6e-
3Sn(OH)62- (aq)+ 6e- +2Bi(s) +
6OH-
3Sn(OH)3-(aq) + 3OH-+
2Bi(OH)3(S)
3Sn(OH)62- (aq)+ 2Bi(s)
This is the balance equation.
-----------------------------------------------------------------------------------------------------
+5 +3 -1 +5
BrO3-(aq) +
Sb3+(aq) Br
- (aq) + Sb5+ (aq)
Oxidation half reaction : Sb3+(aq)
Sb5+ (aq)
Reduction half reaction : BrO3-(aq)
Br
- (aq)
Balancing oxidation half reaction
:Sb3+(aq)
Sb5+ (aq)
Balancing charge ( by adding electrons) : Sb3+(aq)
Sb5+ (aq) + 2e-
---(1)
Balancing Reduction half reaction :
BrO3-(aq) Br
- (aq)
Balancing O atoms ( by adding H2O ) :
BrO3-(aq) Br
- (aq) + 3H2O
Balancing H atoms ( by adding H+ ) :
BrO3-(aq) + 6H+
Br
- (aq) + 3H2O
Balancing charge ( by adding electrons) :
BrO3-(aq) + 6H+
+6e- Br
- (aq) +
3H2O
---(2)
Adding both the equations so that the number of electrons must be balanced on both sides.It can be done as follows:
[3xEqn(1) ] + [1xEqn (2)] gives
3Sb3+(aq)+ BrO3-(aq) +
6H+ +6e-
3Sb5+ (aq) + 6e-+ Br
- (aq) +
3H2O
3Sb3+(aq)+ BrO3-(aq) +
6H+
3Sb5+ (aq) + Br - (aq) +
3H2O
This is the balance equation.