QCEVault

Acids, bases and titration — Question 10

QCAA 2022, Paper 1 · 1 mark

Q10 · 2022 · Paper 1Unclassified1 mark

QUESTION 10

The midpoint of the colour change of a weak acid indicator occurs when

(A) [In−]=[H+]\text{(A) [In}^{-}]=\mathrm{[H}^{+}]

(B) [In−]=[HIn]\text{(B) [In}^{-}]=\mathrm{[HIn]}

(C) [H+]=[OH−]\text{(C) [H}^{+}]=\mathrm{[OH}^{-}]

(D) [HIn]=[OH−]\text{(D) [HIn]}=\mathrm{[OH}^{-}]

Question linkQCAA assessment resources

Related questions

  1. Q3 · 2025 QCAA · Paper 1 · 1 mark
    QUESTION 3 Identify the amphiprotic species. +(aq) (A) NH4 (B) H3O+(aq) 2−(aq) (C) CO3 −(aq) (D) HCO3
    Acids, bases and titration
  2. Q5 · 2025 QCAA · Paper 1 · 1 mark
    QUESTION 5 A 25.00 mL aliquot of aqueous potassium hydroxide (KOH) solution was titrated against an aqueous solution of 0.100 M hydrochloric acid (HCl). It took 17.45 mL of HCl to reach the equivalence point. Determine the concentration of the KOH(aq) solution. (A) 2.29 × 10−1 M (B) 1.43 × 10−1 M (C) 6.98 × 10−2 M (D) 4.36 × 10−5 M
    Acids, bases and titration
  3. Q8 · 2025 QCAA · Paper 1 · 1 mark
    QUESTION 8 Which is the most concentrated weak base? (A) 2.0 M KOH(aq) (B) 0.2 M NaOH(aq) (C) 2.0 M NH4OH(aq) (D) 0.2 M Al(OH)3(aq)
    Acids, bases and titration
  4. Q14 · 2025 QCAA · Paper 1 · 1 mark
    QUESTION 14 Increasing the pH of an aqueous solution of hydrochloric acid (HCl) from 2 to 4 (A) reduces the strength of the acid. (B) increases the acidity of the solution. (C) increases the concentration of H+ ions by a factor of 2. (D) reduces the concentration of H+ ions by a factor of 100.
    Acids, bases and titration