Ferric citrate (C6H5FeO7) 89.4 mM
1.095 g/50 mL
0.328 g/15 mL
The 89.4 value is because Tobias Baskin's lab makes a 89.4 µM Fe-citrate medium, and it's easy to mix up a batch from the 1000x stock solution.
Maximum solubility is 1 g/100 mL hot H2O
Could in the future make a 10 mM batch with 0.1225 g in 50 mL, and for this lab: https://wahoo.nsm.umass.edu/content/reagents-61 , you would have easier calculations.