The half-reaction for the oxidation of the manganese in to .:
Let us say the medium in which reaction is taking place is an acidic medium. And balancing in an acidic mediums done as;
Step 1: Balance all the atom beside oxygen and hydrogen atom;
Manganese and carbon are balanced.
Step 2: Balance oxygen atom adding water on the required side:
Step 3: Now balance hydrogen atom by adding hydrogen ion on the required side:
Explanation:The equation to be balanced is
MnCO3 > MnO2+HCO3-
The oxidation number of Mn changes from +2 in MnCO3 to +4 in MnO2
Therefore two electrons must be added to the right as shown below:
MnCO3 > MnO2+ HCO3-+ 2e-Now,there is one negative charge HCO3- and 1 negative charge on the two electrons making a total of -3 charges on the right. There is zero charge on the left.
To balance the equation,add3H+on the right,to cancel out the charges.
MnCO3 > MnO2+HCO3-+2e-+3H+
Adding H2O to balance Hydrogen and Oxygen atoms: