chapter 9 - electrolysis

Question 1

electrolysis

Answer 1

used to force non- spontaneous redox reactions to occur by the addition of electrical energy
decompose a compound into its constituent elements

Question 2

molten electrolysis

Answer 2

molten made up of 1 anion and 1 cation
- anion loses electrons at anode (oxidised)
- cation gains electrons at cathode (reduced)

anode is positive
cathode is negative

Question 3

aqueous electrolysis

Answer 3

water, ions and, electrodes (unless inert) are present at each electrode and are in competition for best oxidising and reducing agent

reducing agent - bottom right (at anode (positive))
oxidising agent is top left (at cathode (negative))

reactive metal cant be made

Question 4

faradays laws

Answer 4

• the mass of an element deposited at an electrode during electrolysis is directly proportional to the charge in coulombs
• when the same amount of electric current is passed through different electrolytes connected in series, the mass of the substance deposited is directly proportional to the molar mass divided by the charge.

Question 5

charge and curent

Answer 5

Q = I x t
n(e) = Q / F
n(M) = 1/x x n(e) - x = number of electrons
m(e) = 1/x x Q/F x M(element)