sour taste pH equal to 6 turns litmus paper blue forms bubbles with limestone
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: Common soaps are often basic. Which of these is a property of a chemical base?
Possibilities:
- sour taste
- pH equal to 6
- turns litmus paper blue
- forms bubbles with limestone

turns litmus paper blue