← NIC Cosmetology Exam: Chemical Services

Free NIC Cosmetology Exam: Chemical Services Practice Test (2026)

100 questions · 90 min · 75% to pass

100 Questions · 90 Minutes · 75% to Pass

Question 1 of 5

Sample Questions

Question 1

What chemical is the primary active ingredient in an alkaline cold wave perm, and at what pH does it process?

Answer: Alkaline cold wave perms use ammonium thioglycolate as the active ingredient, processing at a pH of 9.0–9.6 at room temperature to break and reform disulfide bonds into a new curl pattern.

Question 2

What is the critical rule regarding applying a sodium hydroxide relaxer to hair that has already been relaxed?

Answer: A relaxer must never be overlapped onto previously relaxed hair; it should be applied only to the new growth to prevent over-processing, severe breakage, and irreversible cortex damage.

Question 3

A client arrives for a relaxer retouch and admits she used a no-lye home relaxer six weeks ago. Why must you identify which relaxer system was used previously?

Answer: Mixing lye and no-lye relaxer systems can cause a chemical reaction that leads to extreme breakage and scalp burns; identifying prior chemical use ensures compatible products are selected.

Question 4

What is the difference between an ammonium thioglycolate relaxer and a sodium hydroxide relaxer in terms of pH and scalp preparation?

Answer: Ammonium thioglycolate (thio) relaxers operate at pH 9–10 and require pre-shampooing before application; sodium hydroxide relaxers are stronger at pH 12–14 and must never be pre-shampooed.

Question 5

Why must a stylist base the scalp before applying a sodium hydroxide relaxer?

Answer: Sodium hydroxide (lye) relaxers have a pH of 12–14, making them highly caustic; applying a petroleum-based basing cream protects the scalp and skin from chemical burns during processing.