General Principles of Isolation

Question 1

Aluminium is used to extract

Answer 1

chromium and manganese

Question 2

Zirconium is heated at _______ in an ______________ with iodine

Answer 2

1800K

evacuated vessel

Question 3

With electrolytic refining, the more ______ metal remains in the solution and the less _____ ones
go to the anode mud.

Answer 3

basic

Question 4

Products of electrolysis of brine?

molten NaCl?

Answer 4

Cl2, NaOH, H2

Na instead of NaOH

Question 5

Steel vessel with lining of carbon acts as

________ and graphite ________ is used.

Answer 5

cathode

anode

Question 6

for each kg of aluminum produced, about ___ kg

of ___________ is burnt away

Answer 6

0.5, carbon anode

Question 7

In Hall Heroult process, The oxygen liberated at
anode reacts with the carbon of anode
producing

Answer 7

CO and CO2

Question 8

The role of reducing agent is to provide

Answer 8

∆rG V negative and large enough to make the sum

of ∆rG V of the two reactions, i.e, oxidation of the reducing agent and reduction of the metal oxide negative.

Question 9

______________________explains why
the reactions are sluggish when every species is in solid state and smooth when the ore
melts down.

Answer 9

Ellingham diagrams

Question 10

Reactions happening at 500-800K in blast furnace

Answer 10

Fe3O4 and Fe2O3 —–> FeO

CaCO3 ——> CaO

Question 11

Reactions happening at 900-1500K

Answer 11

C + CO2 ——–> CO
FeO —–> Fe
CaO + SiO2———> CaSiO3

Question 12

At what temperature does the Fe and CO lines cross

Answer 12

1073K

Question 13

The iron obtained from Blast furnace contains about __% carbon. It is called ___________.
Carbon content of cast iron is _____%

Answer 13

4, pig iron

3

Question 14

Wrought iron is made by?

Answer 14

heating cast iron with haematite

Question 15

For the purpose of heating, the zinc oxide is made into brickettes with

Answer 15

coke and clay

Question 16

In roasting, the ore is heated in a regular supply
of air in a furnace at a temperature ________ the melting
point of the metal

Answer 16

below

Question 17

Collectors used in froth floatation? What do they do?

Answer 17

pine oils, fatty acids, xanthates

enhance non-wettability

Question 18

Froth stabilizers?

Answer 18

cresols, aniline

Question 19

Depressant used in ZnS and PbS? Which does it selectively prevent?

Answer 19

NaCN

ZnS