MnO4- + Cl- right arrow Mn2+ + Cl2

First break the equation into two half reactions, one for Mn and one for Cl

MnO4- right arrow Mn2+

  1. MnO4- right arrow Mn2+
  2. MnO4- right arrow Mn2+ + 4 H2O
  3. 8 H+ + MnO4- right arrow Mn2+ + 4 H2O
  4. 5 e- + 8 H+ + MnO4- right arrow Mn2+ + 4 H2O
  5. 10 e- + 16 H+ + 2 MnO4- right arrow 2 Mn2+ + 8 H2O

Cl- right arrow Cl2

  1. 2 Cl- right arrow Cl2
  2. ...
  3. ...
  4. 2 Cl- right arrow Cl2 + 2 e-
  5. 10 Cl- right arrow 5 Cl2 + 10 e-

10 e- + 16 H+ + 2 MnO8-+ 10 Cl- right arrow 2 Mn2+ + 8 H2O + 5 Cl2 + 10 e-

16 H+ + 2 MnO4- + 10 Cl- right arrow 2 Mn2+ + 8 H2O + 5 Cl2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Basic Solution:

Separate the reaction into two half-reactions.

Balance each half-reaction separately as in acid:

    1. Balance atoms other than O & H by inspection.

    2. Balance O by adding H2O to the opposite side.

    3. Balance H by addding H+ as appropriate.

    4. Balance the charge by adding electrons (e-) - add to same side as excess of positive charge, or opposite side if excess negative charge.

    5. Balance the charges of the two half-reactions by multiplying appropriately.

Balance as in acid above, then:

    1. Add enough OH- (equal numbers to both sides) to cancel the H+. (This is necessary because there will not be protons present in a basic solution!). (There are a couple of other conventions for balancing in basic solutions. If you are familiar with another and prefer it, you may use it instead.)

    2. Combine the H+ and OH- on the appropriate side of the equation to give waters.

    3. Go back and cancel waters which appear on both sides to give the final equation.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Water Properties

 

MW

m.p.

b.p.

Water

18

0°C

100°C

Methane

16

-183°C

-161°C

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Structural diagram of water molecule showing bond angles and lengths

public domain image via Wikipedia Creative Commons

 

 

Space-filling image of water molecule

public domain image via Wikipedia Creative Commons

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

#-D image of H-bonding between space-filling images of water molecules

public domain image via Wikipedia Creative Commons

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Flattened image of the hydration of sodium ion

public domain image via Wikipedia Creative Commons

 

 

 

 

 

 

 

 

© R A Paselk

Last modified 16 February 2015