I did a lab about double replacements and one of the questions is "Why was there no reaction sometimes" and I can not figure it out for the life of me. I checked the chapter we read twice over and still nothing.Please help.We were combining drops of chemicals like KOH and Pb(NO3)2. I know this is kind of tough to answer. http://www.violettes.com/phpBB2/prof...rofile;u=23294