General principles and Processes of Isolation of Elements MCQs

General principles and Processes of Isolation of Elements MCQs

Elements can be found in nature either in a combined state or in a free (native) state. Elements that occur naturally in their free state are relatively rare. Metals that are found in their free state include copper, silver, gold, platinum, and other platinum group metals. Non-metals found in their free state include carbon, sulfur, nitrogen, oxygen, and the noble gases. The form in which an element appears—combined or free—depends on several fundamental factors that are worth investigating. Spectral analysis of distant stars has shown that the distribution of elements in the universe is quite consistent.

In electrorefining of copper, some gold is produced as:

(a) cathode mud
(b) anode mud
(c) cathode deposit
(d) anode deposit

In the equation,

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

(a) copper
(b) iron
(c) gold
(d) zinc

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

(a) lower the melting point of bauxite
(b) dissolve bauxite and render it a conductor of electricity
(c) protect aluminium produced from oxygen
(d) minimise the heat loss due to radiation

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

(a) reduction
(b) carbon-reduction
(c) smelting
(d) roasting

The purest form of iron is:

(a) cast iron
(b) pig iron
(c) wrought iron
(d) steel

Cassiterite is the ore of which metal?

(a) Mn
(b) Sb
(c) Sn
(d) Ni

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

(a) Pb and Zn
(b) Sn and Ag
(c) Fe and Ni
(d) Ag and Au

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

(a) greater solubility of the impurity in molten state than in solid
(b) greater mobility of pure metal than impurity
(c) higher melting point of impurity than that of pure metal
(d) greater noble character of solid metal than that of the impurity

Extraction of zinc from zinc blende is achieved by

(a) electrolytic reduction
(b) roasting followed by reduction with carbon
(c) roasting followed by reduction with another metal
(d) roasting followed by self-reduction

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

(a) FeS
(b) CO
(c) Cu2S
(d) SO2