General principles and Processes of Isolation of Elements MCQs

Elements occur in nature either in the combined state or in a free state. Those occurring in free state or native are few. Metals occurring in free state are copper, silver, gold, platinum and other platinum group metals. Non-metals occurring in free state are carbon, sulphur, nitrogen, oxygen and noble gases. The occurrence of an element in nature in the combined or in the free state depends on certain basic aspects which need to be explored. The abundance of elements in the universe is based on spectral analysis of distant stars. Findings have revealed that there is a remarkable uniformity in this respect.

1. In the equation,

4M + 8CN^– + H₂O + O₂ → 4[M(CN)₂]^– + 4OH^–, the metal M is

1. copper
2. iron
3. gold
4. Zinc

Answer: (c)

2. Heating ore with carbon in the absence of air is known as:

1. reduction
2. carbon-reduction
3. smelting
4. Roasting

Answer: (c)

3. In the extraction of copper from sulphide ore, the metal is formed by reduction of Cu2O with

1. FeS
2. CO
3. Cu2S
4. SO2

Answer: (c)

4. The method of zone refining of metals is based upon the principle of

1. greater solubility of the impurity in molten state than in solid
2. greater mobility of pure metal than impurity
3. higher melting point of impurity than that of pure metal.
4. greater noble character of solid metal than that of the impurity

Answer: (a)

5. Cassiterite is the ore of which metal?

1. Mn
2. Sb
3. Sn
4. Ni

Answer: (c)

6. In electrorefining of copper some gold is produced as:

1. cathode mud
2. anode mud
3. cathode deposit
4. anode deposit

Answer: (b)

7. In the electrolytic method of obtaining aluminium from purified bauxite, cryolite is added to the charge in order to:

1. lower the melting point of bauxite
2. dissolve bauxite and render it a conductor of electricity
3. protect aluminium produced from oxygen
4. minimise the heat loss due to radiation

Answer: (b)

8. The purest form of iron is:

1. cast iron
2. pig iron
3. wrought iron
4. steel

Answer: (c)

9. During the process of electrolytic refining of copper, some metals present as impurity settle as ‘anode mud’. These are:

1. Pb and Zn
2. Sn and Ag
3. Fe and Ni
4. Ag and Au

Answer: (d)

10. Extraction of zinc from zinc blende is achieved by

1. electrolytic reduction
2. roasting followed by reduction with carbon
3. roasting followed by reduction with another metal
4. roasting followed by self-reduction

Answer: (b)