Question

(1 pt) What is [OH-1 at pH 5.5 and pH 10.0? If a fluoride ISE gives a response of +64.7 mV versus SCE when placed in 1.5 x 10-5 M F- at pH 5.5, what would the measured response be at pH 10.0 (assuming no change in ionic strength)? Would you over- or underestimate the fluoride concentration if you tried to use it at pH 10, and by about how much?

The selectivity coefficient for a fluoride ISE is 0.1.

Answer 1

CoH- at pH 5.5 and PH 10.o? t 6 O H Sima lant , 1o Now,accordi na t he quastiar, H 5.5 POH - (44 5.5-8-5 o equation cj ; to -8.5 M 1O iohen = 10.0 4 or, [OH-] = 10-9 n Cs Scannedwith CamScanner