Advertisements
Advertisements
Question
The following questions relate to the extraction of aluminium by electrolysis.
Explain why it is necessary to renew the anode periodically.
Solution
Oxygen gas is liberated at anode as :
\[\ce{O2- - 2e- -> [O] }\]
\[\ce{[O] + [O] -> O2}\]
The oxygen formed at anode oxidizes the carbon of the anode to carbon dioxide.
\[\ce{C + O2 -> CO2}\]
As a result the anode gets oxidized and it has to be replaced periodically.
APPEARS IN
RELATED QUESTIONS
A man went door to door posing as a goldsmith. He promised to bring back the glitter of old and dull gold ornaments. An unsuspecting lady gave a set of gold bangles to him which he dipped in a particular solution. The bangles sparkled like new but their weight was reduced drastically. The lady was upset, but after a futile argument, the man beat a hasty retreat. Can you play the detective to find out the nature of the solution he had used?
Fill in the following blank with suitable word:
The rocky material found with ores is called.............
Which metal is extracted from bauxite ore?
Which of the following metals are extracted by the electrolysis of their molten chlorides?
(a) Na and Hg
(b) Hg and Mg
(c) Na and Mg
(d) Cu and Fe
Which metal can be extracted from the following ore?
Haematite
Answer the following questions based on the extraction of aluminium from alumina by Hall - Heroult’s Process :
What is the function of cryolite used along with alumina as the electrolyte?
Compare the properties of a typical metal and a non- metal on the basis of the following:
(a) electronic configuration
(b) nature of oxides
(c) oxidizing or reducing action
(d) conductivity of heat and electricity
Aluminium oxide is _______ oxide.
In the electrolytic reduction of alumina, the lining of graphite acts as an anode.
Two ores A and B were taken. On heating ore A gives CO2 whereas, ore B gives SO2. What steps will you take to convert them into metals?
