Electrodes and Lab Analytics

Question 1

Do non-polarisable electrodes have resistive or capacitive behaviour?

Answer 1

Resistive

Question 2

What type of reaction occurs at a cathode?

Answer 2

Reduction (gain of electron)

Question 3

How do voltage sources in the skin “talk” to the outside world?

Answer 3

Via membrane resistance

Question 4

Why can’t the individual resistance of a cell be measured?

Answer 4

Masked by mass tissue resistnace

Question 5

What type of electrode, polarising or non-polarising, is ideal for skin electrode?

Answer 5

Non-polarising (resistive behaviour)

Question 6

What are two major problems with skin measurements?

Answer 6

Two electrodes with different potentials can mask potential trying to measure
Varying chemical environments of two electrodes

Question 7

What are the ideal properties of the differential amplifier in a skin electrode system?

Answer 7

Rin high as possible

Electrode resistance as low as possible

Question 8

Is a siver chloride electrode polarisable or non-polarisable?

Answer 8

Non-polarisable

Question 9

What is the activity of chloride ions?

Answer 9

Approximately 1, doe to high concentration in biological fluids

Question 10

What was the problem with 1st generation glucose sensors?

Answer 10

Depend on the the concentration of O2 in the blood