| Date | November 2013 | Marks available | 1 | Reference code | 13N.1.hl.TZ0.27 |
| Level | HL | Paper | 1 | Time zone | TZ0 |
| Command term | Identify | Question number | 27 | Adapted from | N/A |
Question
What is the relationship between \({\text{p}}{K_{\text{a}}}\), \({\text{p}}{K_{\text{b}}}\) and \({\text{p}}{K_{\text{w}}}\) for a conjugate acid–base pair?
A. \({\text{p}}{K_{\text{a}}} = {\text{p}}{K_{\text{w}}} + {\text{p}}{K_{\text{b}}}\)
B. \({\text{p}}{K_{\text{a}}} = {\text{p}}{K_{\text{w}}} - {\text{p}}{K_{\text{b}}}\)
C. \({\text{p}}{K_{\text{a}}} \times {\text{p}}{K_{\text{b}}} = {\text{p}}{K_{\text{w}}}\)
D. \(\frac{{{\text{p}}{K_{\text{a}}}}}{{{\text{p}}{K_{\text{b}}}}} = {\text{p}}{K_{\text{w}}}\)
Markscheme
B
Examiners report
[N/A]
