Hi everyone. I'm troubleshooting the [Co(en)3]3+ prep from Girolami, Rachfuss and Angelici. The prep, briefly, is to take 6 g Co salt, 13 g en·2 HCl, 25 mL water, 8 g NaOH and then 20 mL of 3% H2O2. Then it says to dilute to 50 mL and heat to boiling. However, at the end of the addition, the volume is 70+ mL. My student yields were really low this spring (much lower than usual) so I am wondering if anyone else has worked on this. I just set it up for the first time ever (I did the old "pull air through the solution" from the previous edition by Angelici 25 years ago...) and the reaction works fine, its just too dilute to get a good yield. Thoughts? Ideas? thanks.