# pH and solute solubility in waste mixed water

I was reading a module on waste management. There were two interesting points.

1. High pH results in higher solubility of $\ce{CN-}$. I understand that for HCN: $$\ce{HCN ->H+ + CN-}$$

Higher pH means that equilibrium will be shifted rightwards and concentration of $\ce{CN-}$ will increase. But will cyanide salts like KCN, NaCN have the same high solubility at higher pH? If so, how?

2. Low pH results in greater solubility of toxic gases. How?

• 1. HCN is a weak acid, so its salts get hydrolyzed to a significant extent, which makes the same argument applicable. 2. This is an example of hasty generalization. What toxic gases are you talking about? – Ivan Neretin Oct 27 '16 at 14:49
• Actually the book doesn't mention the gas names. Well, I don't think it will be SO2, CO2 because they will dissolve better in greater pH. Maybe alkaline toxic gases do the work – Mockingbird Oct 27 '16 at 15:26
• You think right. NH3 may behave like that. – Ivan Neretin Oct 27 '16 at 15:29