Quiz on Electrochemical Analysis and Heavy Metals

Which of the following is NOT a common heavy metal found in contaminated water?

• Mercury (Hg)

• Lead (Pb)

• Zinc (Zn)

• Sodium (Na)

What is the role of the reference electrode in an electrochemical cell?

• To provide a stable potential

• To measure the current

• To act as the working electrode

• To change the solution concentration

What does the Nernst Equation relate to in electrochemical analysis?

• Redox reactions

• Cell potential and concentration

• Volume and mass

• Current and resistance

What happens to the electrode potential as the ion concentration (E.g: Pb²⁺) decreases?

• It becomes more negative

• It remains constant

• It fluctuates randomly

• It becomes more positive

Which of the following is a common reference electrode?

• Ion-selective electrode

• Metal electrode

• Glass electrode

• Saturated Calomel Electrode (SCE)

What is a significant challenge in measuring Pb²⁺ and Cd²⁺ using ISEs?

• Interference from other ions

• Inability to measure low concentrations

• High cost of electrodes

• Limited portability

What does a positive E° value indicate about a reaction?

• The reaction is non-spontaneous

• The reaction is spontaneous

• The reaction is at equilibrium

• The reaction is impossible

Which of the following describes a redox reaction?

• Electrons are transferred between species

• No electron transfer occurs

• Only oxidation occurs

• Only reduction occurs

What is the purpose of a salt bridge in an electrochemical cell?

• To increase the temperature

• To prevent ion transfer

• To connect the two half-cells

• To measure the current

What is the standard reduction potential (E°) of the standard hydrogen electrode (SHE)?

• 0.059 V

• 0.000 V

• -0.059 V

• 1.000 V