Final answer:
The polarographic (Clark) electrode measures the partial pressure of O2 by means of an oxygen-dependent chemical reaction that generates a proportional electric current.
Step-by-step explanation:
The polarographic (Clark) electrode measures partial pressure of O2 by:
Absorbing infrared light
Detecting ionized particles
Oxygen-dependent chemical reaction
Measuring electrical resistance
The correct answer is C) Oxygen-dependent chemical reaction. The polarographic electrode works by measuring the oxygen-dependent chemical reaction that occurs at the electrode surface. Oxygen diffuses to the electrode and reacts with a chemical coating, producing an electrical current that is directly proportional to the oxygen concentration.
The polarographic (Clark) electrode measures the partial pressure of O2 using an oxygen-dependent chemical reaction. When oxygen diffuses through a membrane and comes into contact with an electrolyte solution that contains a cathode and an anode, a chemical reaction occurs. This reaction reduces the oxygen, which in turn generates a current that can be measured. The strength of the current is directly proportional to the partial pressure of oxygen in the surrounding environment. Therefore, the correct answer to the question is C) Oxygen-dependent chemical reaction.