ASVAB · Chemistry

What is the pH of a neutral substance?

Correct answer

7

  1. A 10
  2. B 0
  3. C 7
  4. D 14

Why this is the answer

The pH SCALE: 0-14 scale measuring hydrogen ion concentration. pH 7 = NEUTRAL (pure water); pH below 7 = ACIDIC (more H+ ions); pH above 7 = BASIC/ALKALINE (more OH- ions). Each unit represents a 10x change: pH 6 is 10x more acidic than pH 7; pH 5 is 100x more acidic. COMMON pH VALUES: Battery acid ~0-1; stomach acid ~1.5-3.5; vinegar ~2.4; coffee ~5; milk ~6.5; water 7; blood ~7.4; baking soda ~8.3; bleach ~12.5; drain cleaner ~14. ACID + BASE → SALT + WATER (neutralisation reaction). The litmus test: red = acid; blue = base.
Source: ASVAB GS, Chemistry — pH Scale

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About this topic: Chemistry

Chemistry questions cover atomic structure, the periodic table, chemical versus physical changes, acids and bases, and basic reactions. Expect symbols, states of matter and the difference between an element, a compound and a mixture. This is one of 12 General Science questions on chemistry, each with a full explanation on a single study page.

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