Washington Master Esthetics Practice Exam

What is the pH value of a 70% glycolic acid solution?

1. 1.0

2. 4.0

3. 7.5

4. 0.6

The correct answer is: 0.6

The pH value of a solution represents its acidity or alkalinity, with lower values indicating higher acidity. Glycolic acid is a type of alpha hydroxy acid (AHA) commonly used in skincare for its exfoliating properties. A 70% glycolic acid solution is very concentrated, meaning it contains a high percentage of glycolic acid, which would lead to a significantly low pH. In the case of glycolic acid at this concentration, a pH value around 0.6 makes sense because it reflects a highly acidic solution. This low pH would strongly indicate that the solution is very potent, and it's important to handle such concentrations with care, as they can cause skin irritation or chemical burns if not used properly. The other choices, such as 1.0, 4.0, and 7.5, reflect less acidic environments. For instance, a pH of 4.0 would represent a more diluted solution or a less acidic formulation, more suitable for everyday topical use but not reflective of a highly concentrated glycolic acid solution. Therefore, the pH of 0.6 accurately represents the highly acidic nature of a 70% glycolic acid solution, establishing it as the correct answer in this