In equation (A) there is the reaction happening when you dissolve formic acid in water to form a solution (formic acid have a weak acidic character).
In equation (B) there is the reaction happening when you dissolve methyl-amine in water to form a solution (methyl-amine have a weak basic character).
In equation (C) you may see the reaction that you obtain when the formic acid solution and methyl-amine solution are mixed together.
