Phlebotomy Technician Practice Exam (NCPT/CPT)

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Prepare effectively for the NCPT/CPT Phlebotomy Technician Exam. Utilize flashcards and multiple-choice questions with hints and explanations to excel in your exam.

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An effective disinfectant is comprised of what percentage of H2O?

  1. 80%

  2. 90%

  3. 95%

  4. 70%

The correct answer is: 90%

An effective disinfectant is comprised of 90% H2O because water is a polar molecule that can surround the bacteria or virus and disrupt their outer membranes, ultimately killing them. The other options are incorrect because they have a lower concentration of water, making them less effective in killing pathogens. For example, option A, which is 80%, may not have enough water to sufficiently destroy the outer membrane of the microorganism, while option C (95%) may have too much water, diluting the active ingredients of the disinfectant. Option D (70%) is also incorrect because it has an even lower concentration of water, making it less effective in disrupting the pathogens' outer membranes. Therefore, the optimal percentage of H2O in an effective disinfectant is 90%, allowing for maximum effectiveness in killing harmful microorganisms.