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Chemical services practice questions

15 questions from the barber theory practice test.

Chemical services practice test

10 questions, graded as you go, with the reason for every answer. No sign-up.

What this covers

Sample questions

Which side bonds must be broken chemically to change the natural curl pattern of hair permanently?

  1. Hydrogen bonds
  2. Disulfide bonds
  3. Salt bonds
  4. Peptide bonds
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B. Disulfide bonds

Disulfide bonds are the strong chemical side bonds; permanent waving and relaxing work by breaking them. Hydrogen bonds are broken by water alone, which only gives a temporary change such as a wet set.

Reference: Barbering theory: chemical services (chemistry of texture services)

What does the neutralizer do in a permanent wave?

  1. Breaks the disulfide bonds so the hair takes the rod shape
  2. Swells the cuticle so the waving lotion can enter
  3. Rebuilds the disulfide bonds in the new curled shape
  4. Coats the hair to protect it from the waving lotion
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C. Rebuilds the disulfide bonds in the new curled shape

The neutralizer is an oxidizer that stops the action of the waving lotion and re-forms the disulfide bonds in their new positions around the rod. Breaking the bonds is the job of the waving lotion, the step before.

Reference: Barbering theory: chemical services (permanent waving)

During a perm, a test curl is unwound part way and the hair forms a firm, well-defined S pattern. What does that show?

  1. Processing is complete and the hair is ready to rinse
  2. Processing has only just begun and more time is required
  3. The hair is overprocessed and should be cut shorter
  4. The neutralizer was applied before the waving lotion
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A. Processing is complete and the hair is ready to rinse

A firm S-shaped wave that matches the rod size is the sign that enough bonds have been broken, so the lotion is rinsed and the hair neutralized. A weak or undefined wave would mean more processing time is needed.

Reference: Barbering theory: chemical services (permanent waving)

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