| Date | May 2009 | Marks available | 1 | Reference code | 09M.1.hl.TZ1.27 |
| Level | HL | Paper | 1 | Time zone | TZ1 |
| Command term | Identify | Question number | 27 | Adapted from | N/A |
Question
What is the correct expression for the ionic product constant of water, \({K_{\text{w}}}\)?
A. \({K_{\text{W}}} = \frac{{{\text{[}}{{\text{H}}^ + }{\text{]}}}}{{{\text{[O}}{{\text{H}}^ - }{\text{]}}}}\)
B. \({K_{\text{W}}}{\text{ = }}\frac{{{\text{[}}{{\text{H}}_2}{\text{O]}}}}{{{\text{[}}{{\text{H}}^ + }{\text{][O}}{{\text{H}}^ - }{\text{]}}}}\)
C. \({K_{\text{W}}} = {\text{[}}{{\text{H}}^ + }{\text{]}} + {\text{[O}}{{\text{H}}^ - }{\text{]}}\)
D. \({K_{\text{W}}} = {\text{[}}{{\text{H}}^ + }{\text{][O}}{{\text{H}}^ - }{\text{]}}\)
Markscheme
D
Examiners report
[N/A]
