21. Which of the following is a characteristic of a half-cell?
a) It consists of an anode only
b) It consists of a cathode only
c) It consists of both an anode and a cathode
d) It consists of a salt bridge and an electrolyte
22. Which of the following is used as a reference electrode in electrochemical measurements?
a) Platinum electrode
b) Silver chloride electrode
c) Zinc electrode
d) Copper electrode
23. Which of the following is not a factor that affects the cell potential of an electrochemical cell?
a) Concentration of electrolytes
b) Temperature
c) Surface area of electrodes
d) Length of the salt bridge
24. What is the standard hydrogen electrode (SHE)?
a) An electrode made of hydrogen gas
b) An electrode made of platinum
c) An electrode made of silver chloride
d) An electrode made of zinc
25. Which of the following is the standard electrode potential for the standard hydrogen electrode?
a) 0 V
b) +1 V
c) -1 V
d) +2 V
