Balance the following chemical equation
`MnO_(2)+HCl to MnCl_(2)+H_(2)O+Cl_(2)`

Explanation

Step 1: Assign oxidation number:
`overset(+4-2)(MnOI_(2))+overset(+1-1)(HCl)tooverset(+2-1)(MnCl_(2))+overset(0)(Cl_(2))+overset(+1)(H_(2)overset(-2)(O)`
Step 2: Write the oxidation number changes.
Change in oxidation number of `Mn+4` to `+2=2`
change in oxidation number of Cl-1 to 0=+1 `MnO_(2)+2HCl to MnCl_(2)+H_(2)O+Cl_(2)`
Step 4, Check the oxidation number, and 2 molecules of HCl on left hand side to balance the chlorine atoms of `MnCl_(2)`. In order to balance oxygen and hydrogen atom 2 molecule of `H_(2)O` has to be added to the right hand side.
`MnO_(2)+4HCl to MnCl_(2)+2H_(2)O+Cl_(2)`