RP electrolysis

Question 1

equipment list

Answer 1

-copper(II) chloride solution
-sodium chloride solution
-petri dish lid
-two carbon rod electrodes
-two crocodile clips
-power supply
-blue litmus paper
-forceps
-beaker

Question 2

method

Answer 2

1. add 50cm³ copper chloride solution to a beaker
2. add the lid and insert electrodes through the holes making sure they aren’t touching
3. attach crocodile clips to the electrodes and connect to a low voltage power supply
4. select 4V and switch on
5. using the forceps hold the litmus paper near the anode and identify element
6. observe cathode
7. repeat with sodium chloride

Question 3

results

Answer 3

-chlorine gas produced at anode both times, bleaches litmus paper white & bubbles seen
-copper solid formed at cathode for copper chloride, brown/red coating on electrode
-hydrogen gas formed at cathode for sodium chloride, rapid bubbles of gas/effervescence

Question 4

safety

Answer 4

-safety goggles worn
-room well ventilated as large quantities of chlorine is toxic

Question 5

what forms at the anode and cathode generally?

Answer 5

anode-non-metals
cathode-metals or hydrogen

Question 6

half equations at anode and cathode for CuCl₂

Answer 6

cathode-Cu²⁺ + 2e⁻ –> Cu
anode-2Cl²⁻ –> Cl₂ + 2e⁻

Question 7

half equations for anode and cathode for NaCl

Answer 7

cathode-2H⁺ + 2e⁻ –> H₂
anode-2Cl⁻ –> Cl₂ + 2e⁻

Question 8

how to test chlorine gas was produced at anode?

Answer 8

bleach litmus paper white

Question 9

how to test hydrogen gas product?

Answer 9

squeaky pop

Question 10

how to test oxygen gas produced?

Answer 10

relights a glowing splint