Soaps are alkali , which is why they are bitter and slippery . Alkalis have a pH (potential hydrogen ) of 7-12 . Lemon juice is acidic which would neutralize the alkalinity of the soap . Acids have pH of 1-6 . It would cause the pH of the soap to drop .
It would cause the ph of both of them mixed to neutralize. The ph of soap is a base and somewhere between 8-14 while the lemon has a ph between 0-6. This will cause their ph to become somewhere around 7 or neutral.
