Dear Student, The pH scale varies from 0 to 14. A pH value from 0 to 6.9 represents acidic solutions, while a pH value from 7.1 to 14 represents basic solutions. A pH value of 7 indicates that a solution is neither acidic nor basic i.e. it is neutral. Lemon juice has citric acid that has pH 2, as acids have pH 0 to 6.9 so lemon juice is acidic. Regards