The salt bridge is essential in maintaining electrical neutrality in a Daniell cell. In the absence of a salt bridge, the two compartments will accumulate the opposite charges and prevent further reaction. For the salt bridge to function properly, there must be an appropriate electrolyte. Which of the following statements most accurately explains whether an electrolyte is appropriate for the salt bridge in the following electrochemical cell?
2Ag+(aq)​+Cu(s)​→2Ag(s)​+Cu2+(aq)
  • is not appropriate because polyatomic ions such as the sulfate ion will oxidize more easily than water.
  • KOH is not a good choice because potassium has a very positive reduction potential.
  • CuS is a good choice because neither the cation and anion will react with the ions in the compartments.
  • KCl is not appropriate because this compound will react with the ions in the compartments.