IB Chemistry HL 3.1.13 Hl Ph Curves for Weak Acids Bases Questions

Use real HL exam questions to sketch and classify weak/strong titration curves, locate pKa or pKb at half-equivalence, and interpret key species.

Exam points

Identify or sketch the characteristic pH-curve shape for strong/weak acid and base combinations, including the direction, buffer region and steep change.
Deduce whether the equivalence-point pH is below, at or above 7 from the reacting acid and base strengths and locate the equivalence volume on the curve.
Use a weak-acid or weak-base titration curve to locate the buffer or half-equivalence point and determine pKa or pKb.
Interpret a marked point on a titration curve to identify the major species or the salt-only composition.

[Maximum number: 3]

When nitrogen gas and hydrogen gas are allowed to react in a closed container the following equilibrium is established.

\mathrm{N}_{2}(\mathrm{~g})+3 \mathrm{H}_{2}(\mathrm{~g}) \rightleftharpoons 2 \mathrm{NH}_{3}(\mathrm{~g}) \quad \Delta H=-92.6 \mathrm{~kJ}

Sketch the pH tiration curve obtained when $50.0 \mathrm{~cm}^{3}$ of $0.100 \mathrm{moldm}^{-3} \mathrm{NH}_{3}(\mathrm{aq})$ is added to $25.0 \mathrm{~cm}^{3}$ of $0.100 \mathrm{~mol} \mathrm{dm}^{-3} \mathrm{HCl}$ (aq).

Figure for Question IB Chemistry HL 3.1.13 Hl Ph Curves for Weak Acids Bases Questions question 1 — IB Chemistry HL

Figure for Answer to Question IB Chemistry HL 3.1.13 Hl Ph Curves for Weak Acids Bases Questions question 1 — IB Chemistry HL

For volume =0: pH=1;
vertical jump should be positioned in volume range $24 \mathrm{~cm}^{3}$ to $26 \mathrm{~cm}^{3}$ and include pH range between 3 to 6;
For volume =50 : pH between 8 to 11;

All question bank results loaded

IB Chemistry HL 3.1.13 Hl Ph Curves for Weak Acids Bases Questions question 1