ELECTROLYSIS

Question 1

What is electrolysis?

Answer 1

the process that uses energy to break down ionic compounds into elements.

Question 2

what is the positive and the negative electrode called?

Answer 2

the positive one is ANODE and the negative one is CATHODE.

Question 3

where do the positively charged atoms go during electrolysis?

Answer 3

the positively charged atoms go to the cathodes as opposites attract.

Question 4

where do the negatively charged atoms go during electrolysis?

Answer 4

the negatively charged electrons go to the anodes as opposites attract

Question 5

what happens when the atom reaches the electrode?

Answer 5

it changes from an ion to a molecule.

the positively charged ion would go to the cathode, where it receives electrons to make it neutral. visa versa

Question 6

how is aluminium extracted? (5 points)

Answer 6

1) Aluminium is extracted from the ore Bauxite by electrolysis. Bauxite contains aluminium oxide.
2) aluminium oxide has a very high melting point so it is mixed with Cryolite to lower the melting point
3) the molten mixture contains free ions- so it will conduct electricity
4) Al(3+) goes to the cathode & turn into neutral aluminium atoms. these then sink to the bottom of the tank
5) O2(-) are attracted to anodes. the oxygen reacts with the carbon anodes to produce co2

Question 7

what is the problem with using carbon electrodes for the extraction of aluminium?

Answer 7

the carbon anode gradually burns away and have to be replaced energy

Question 8

other than the ionic compound, what other ions are in an aqueous solution?

Answer 8

hydrogen ions ( H+) and hydroxide ions ( OH-) from the water 
H20 === (H+) + (OH-).  (half equation)

Question 9

where and when is hydrogen gas formed?

aqueous

Answer 9

hydrogen gas is formed at the cathode, if the other ion is more reactive than it.

Question 10

when and where is oxygen formed?

aqueous

Answer 10

oxygen is formed at the anode if there are no halide ions present