Representing Cells

Question 1

What is an electrode potential?

Answer 1

• The potential difference between the rod and the solution

Question 2

What does the potential difference depend on?

Answer 2

• Nature of the ions
• Concentration of the ions
• Type of electrode used
• Temperature of system

Question 3

What is the Electrode Potential Value (E)?

Answer 3

• Shows how easily a substance is reduced
• And shows the polarity of the RIGHT HAND ELECTRODE

Question 4

What does a more positive E value tell us?

Answer 4

• More likely for the species to undergo reduction
• Equilibrium position lies more to the right
• Electrons flow from the more negative cell to the more positive one

Question 5

What does a more negative E value tell us?

Answer 5

• Species is more likely to undergo oxidation
• Equilibrium lies to the left

Question 6

What is the phase boundary?

Answer 6

• Interface between a solid and a solution
• Represented by a solid vertical line

Question 7

What is a salt bridge?

Answer 7

• Contains mobile ions which complete the circuit
• ## Potassium chloride or nitrate usually (they are soluble, so no precipitates form which would affect equilibrium position and thus electrode potential)(Generally, substances with the highest oxidation state are drawn next to the salt bridge)

Question 8

How do you construct a half cell?

Answer 8

• More negative (more likely to be oxidised) on the left
• Higher oxidation state next to salt bridge