Finding ions in water samples So for a school chemistry assignment I was given 5 water samples and a bunch of different reagents to help me find out what was in the solutions. I'm  stuck on two.

The first one had a pH of 7 and only reacted with silver nitrate and formed a white precipitate. the second had a pH of 14 and turned brown when silver nitrate was added to it. Does anyone know of any chemicals that would do this?
It's Silver(I) Hydroxide

The solution was very alkaline, as evident by it's pH value of 14. Although  $\ce{AgOH}$ is sparingly soluble, with a $K_{\text{sp}}$ of $\pu{6.8×10^{-9}}$, under alkaline conditions it precipitates as a brown solid. 

This is a picture of precipitating silver hydroxide. Is it what you saw as well?