Extraction of Aluminium

Q. 42. A+B gives C+D, Kc for this reaction is 10.if1, 2, 3, 4 mole /litre of A, B, C, D respectively are present in a container at 25C, the direction of reaction will be

Q.

The chemical formula of Cryolite an important mineral of aluminium is:

1. AlCl₃.H₂O

2. Na₃AlF₆

3. Al₂O₆

4. Al₂O₃.2H₂O

Q. 47. Arrange in the increasing Order of melting point of following i) liI NaI ki rbI CsI ii)bef2 mgf2 caf2 srf2 baf2

Q. what is the percentage strength of a solution of 100 volume hydrogen peroxid

Q. KCl, CuCl, CuCl2 melting point order

Q. What is the formula for Pepsi

Q.

The bauxite ore of aluminium is concentrated by froth flotation

1. True

2. False

Q.

$Pb{O}_2+2NaOH\to$ ______$+H_{2}O$

1. Na₂PbO₂

2. Na₂PbO₃

3. Na₂PbO

4. None of these

Q. Why are potassium and caesium used, rather than lithium used in photoelectric cells?

Q.

Electrolytic reduction of alumina to aluminium by Hall-Heroult process is carried out:

1. in the presence of NaCl

2. in the presence of fluorite

3. in the presence of cryolite which forms a melt with a lower melting temperature

4. in the presence of cryolite which forms a melt with a higher melting temperature

Q.

During the electrolytic extraction of Aluminium, purified alumina is mixed with $N{a}_3$ $Al{F}_6$ and $Ca{F}_2$. Why?

1. They increase the conductivity.

2. They increase the melting point of the mix.

3. They decrease the conductivity.

4. They decrease the melting point of the mix.

Q.

Which of the following is not related to the extraction of Aluminium?

1. Bayer’s process

2. Bauxite

3. Rutile

4. Hall-Heroult process

Q. Metal oxides of Ti, Cr and Fe can be reduced by Al in the Aluminothermic process.

1. True
2. False

Q.

In the commercial electrochemical process for Aluminium extraction, the electrolyte used is:

1. $Al(OH{)}_3$ in NaOH

2. An aqueous solution of $A{l}_2(S{O}_4{)}_3$

3. A molten mixture of $A{l}_2{O}_3$ & $N{a}_{3}Al{F}_6$

4. A molten mixture of $A{l}_2{O}_3$ & $Al(OH{)}_3$

Q. The bauxite ore of aluminium is concentrated by froth flotation method

1. True
2. False

Q. What is the formula for Pepsi

Q. Melting point increase upto arsenic and then decreases

Q. In the context of the Hall-Heroult process for the extraction of Al, which of the following statements is false?

1. $CO$ and $C{O}_2$ are produced in this process

2. $A{l}_2{O}_3$ is mixed with $Ca{F}_2$, which lowers the melting point of the mixture and brings conductivity

3. $A{l}^{3+}$ is reduced at the cathode to form $Al$

4. $N{a}_{3}Al{F}_6$ serves as the electrolyte

Q. The amphoteric nature of aluminium is exploited in which of the following processes for the extraction of aluminium?

1. Bayer’s process
2. Hall’s process
3. Serpek’s process
4. Dow’s process

Q. Name the metal which floats on water without any apparent reaction with water.

1. Magnesium
2. Mercury
3. Lithium
4. Gallium

Q. The process that yields 99.99% pure aluminium is:

1. Serpeck's process

2. Hall-Heroult process

3. Hoope's process

4. Bayer's process

Q.

Complete the following

$2A{l}_2{O}_3+3C\to 4A+3B$. A & B are as follows.

1. Al, CO

2. CO, Al

3. Al, $C{O}_2$

4. $C{O}_2,Al$

Q.

a 0.2076g sample of an oxide of cobalt on analysis was found to contain 0.1476g cobalt. calculate the empirical formula of the oxide .[co=59amu]