Explore BrainMass
Share

Ion selective electrode problem

This content was STOLEN from BrainMass.com - View the original, and get the already-completed solution here!

The data below is obtained with a potassium ISE. To avoid interferences from H+ and
variations in ionic strength all solutions were made to contain 0.33 M Ca(NO3)2 and
0.0010 M NaOH. An unknown solution was similarly prepared and gave a reading of
-0.0273 volts.

a) What is the slope of the ISE response? (This is the same as the coefficient of the log
term in the ISE equation). What is the value of E', (also known as k)?
b) What is the concentration of K+ in the unknown?
c) What is the lowest [K+] value that can be accurately measured using the ISE and the
procedure described?
d) What is selectivity constant, kK,Na , for the ISE?

Log [K+] E (volts)
-1.3 -0.165
-2.3 -0.221
-3.0 -0.259
-3.7 -0.298
-4.7 -0.350
-5.3 -0.381
-6.3 -0.413
-7.0 -0.421
-8.0 -0.424
-9.0 -0.424

© BrainMass Inc. brainmass.com October 16, 2018, 4:02 pm ad1c9bdddf
https://brainmass.com/chemistry/oxidation-reduction-and-electrochemistry/ion-selective-electrode-problem-11547

Attachments

Solution Preview

See the attachment. Thanks.

The data below is obtained with a potassium ISE. To avoid interferences from H+ and
variations in ionic strength all solutions were made to contain 0.33 M Ca(NO3)2 and
0.0010 M NaOH. An unknown solution was similarly prepared and gave a reading of
-0.0273 volts.

a) What is the slope of the ISE response? (This is the same as the coefficient of the log
term in the ISE equation). What is the value of E', (also known as k)?
b) What is the concentration of K+ in the unknown?
c) What is the lowest [K+] value that can be accurately measured using the ISE and the
procedure described?
d) What is selectivity constant, kK,Na ...

Solution Summary

Ion selective electrode problems are analyzed for potassium ISE. The solution is given in the attachment in 450-500 words including tables.

$2.19
Similar Posting

Neuron Bathed in Muscimol & Baclofen

Please see the attached figure. This is from the cerebellum of a rat.

Plate 1 shows the normal activity of a neuron. Plate 2 shows the activity of a neuron after being bathed in muscimol (a GABAa agonist). Plate 3 shows the activity of a neuron after being bathed in balcofen (a GABAb agonist). Plate 4 shows the wash out of drugs. Explain this figure (i.e. what is happening at the synapse? Why is one type of GABA agonist more effective than the other? Explain how each receptor functions to affect synaptic activity.

View Full Posting Details