A solution with pH = 4 is:
ABasic (above pH 7)
BAcidic (10⁻⁴ M H+, well below pH 7)
CNeutral (only at exactly pH 7)
DStrongly basic (pH below 7 is basic)
Answer & Solution
Correct answer: B. Acidic (10⁻⁴ M H+, well below pH 7)
pH < 7 = acidic. pH 4 means [H+] = 10⁻⁴ M, more acidic than water. Common examples: lemon (pH 2), vinegar (3), tomato (4), milk (6.5). Acidic solutions turn blue litmus red.
Related questions
For the dissociation of a weak acid HA, the degree of dissociation α is given (approximateAccording to Brønsted-Lowry, an acid is a substance that:If Q (reaction quotient) > K_c at some instant, the reaction will:Le Chatelier's principle states that a system at equilibrium under stress:K_sp of a sparingly soluble salt AB at 25 °C is 4 × 10⁻¹⁰. Molar solubility s of AB is:A buffer solution is most resistant to pH change when:K_w (ionic product of water at 25 °C) is:The pH of a 0.01 M HCl solution is: