20. ELECTROCHEMISTRY

Question 1

What is discharged at the electrodes

Answer 1

• at cathode, metal with highest E*

- at anode, anion with lowest E* expect halogens which will ALWAYS be discharged. F->Cl->Br->I (overpotential)

Question 2

How to write an ionic equation

Answer 2

• more positive E* will be reduction
• more negative E* will be oxidation
• balance the electrons

Question 3

Which species is an oxidising agent

Answer 3

species with most positive E*

Question 4

Which species is a reducing agent

Answer 4

species with most negative E*

Question 5

How to figure out if a reaction occurs

Answer 5

• if one of the two given species can be oxidised and the other reduced, reaction occurs
• equation written with the species swapped according to whether oxidation/reduction taking place
• equation balanced

Question 6

What are formulae for calculating avogadro constant

Answer 6

L = number of moles of electrons/number of electrons

L = total charge of electrons(Faraday Constant)/charge on one electron

Question 7

What is the conversion from cm^3 to dm^3

Answer 7

x10^-3

Question 8

What colour is FeSO4

Answer 8

pale green