Which of the following statement(s)is(are)TRUE for coulometry?
I Coulometric methods count electrons used in a chemical reaction to measure analyte.
II Coulometry employs either constant-current or constant-potential conditions.
III An advantage of coulometric methods is high precision and a disadvantage is low sensitivity.
IV Coulometric titrations are constant-potential methods.
V Constant-potential methods utilizing a three-electrode cell are more selective than constant-current methods.

Question

Quizplus · Accepted Answer

Statement I is true as coulometry measures the amount of charge passed through the system, which is directly proportional to the number of electrons used in the chemical reaction. 
Statement II is true as coulometry can be conducted under constant-current or constant-potential conditions. 
Statement V is true as constant-potential methods utilizing a three-electrode cell are more selective than constant-current methods. 
Statements III and IV are false as coulometric methods have high sensitivity but low precision and coulometric titrations are constant-current methods.

Which of the Following Statement(s)is(are)TRUE for Coulometry