piperazine-N,N’-bis(ethanesulfonic acid); 1,4-piperazinediethanesulfonic acid, CAS NUMBER: 5625-37-6, Sigma P6757
- pKa at 25C of 6.8 (a second one at pH 3 is not of interest)
- usable buffering range of 6.1 to 7.5
- molecular weight 302.4
- ΔpKa/ΔT = -.0085
Buffers are typically 0.5 M, prepared by neutralizing PIPES with sodium hydroxide. PIPES is essentially insoluble until it is neutralized.