- #1
Telemachus
- 835
- 30
What should be the molarity in an aquatic dissolution for Trimethylamine, ##(CH_3)_3N## if ##pH=11,2##?
##(CH_3)_3N+H_2O \rightleftharpoons (CH_3)_3NH^++OH^-##, ##K_b=6.3 \times 10^{-5}##
I know that ##pH+pOH=14 \rightarrow pOH=2.8##, then ##[OH^-]=1.58 \times 10^{-3}##
And ##K_b=\displaystyle\frac{ [ (CH_3)_3NH^+] [OH^-]}{[(CH_3)_3N]}## I used the approximation that water remains constant.
I think I should use some other approximation to get the concentration for ##(CH_3)_3N##, but I'm not sure.
##(CH_3)_3N+H_2O \rightleftharpoons (CH_3)_3NH^++OH^-##, ##K_b=6.3 \times 10^{-5}##
I know that ##pH+pOH=14 \rightarrow pOH=2.8##, then ##[OH^-]=1.58 \times 10^{-3}##
And ##K_b=\displaystyle\frac{ [ (CH_3)_3NH^+] [OH^-]}{[(CH_3)_3N]}## I used the approximation that water remains constant.
I think I should use some other approximation to get the concentration for ##(CH_3)_3N##, but I'm not sure.