What is the product of these reactions
HNO3+Mn(OH)2

HNO3 is an acid (nitric acid)
Mn(OH)2 is a base (manganous hydroxide)

Acids dissolve (in water) to give hydrogen ions (H+)
Bases dissolve to give hydroxide ions (OH-)

You should be able to figure out what the counter-ions are and what happens when you allow an acid to react with a base.