When drops of lemon juice are put on blue litmus it turns red what will happen if you put drops of soap solution on the same position on litmus paper with that same apparatus procedures?

Answer 1

"Soap" is a little vague, but most soaps are somewhat alkaline and if I were forced to bet on what would happen I would guess that the litmus would turn blue again. However, depending on the kind of soap, it might do nothing except get it wet and soapy.

Answer 2

The color is unchanged.