Arrange these in increasing order of their pH values- NaOH, blood, lemon juice.
The pH scale measures the concentration of H+ions, it expresses the acidity and basicity of a substance. Acid is a substance ( molecule or ion) that has a tendency to donate H+ions, and its pH value lies between 0-7. The base is a substance (molecule or ion) that has a tendency to accept H+ions and donate OH-ions, and its pH value lies between 7-14. Since lemon juice has a pH level of 2.2 - 2.4, blood has a pH level of approx 7, NaOH solution has a pH level of 14. The order is as follows: Lemon juice < blood < NaOH solution.
