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BoardChemistry

General Principles and Processes of Isolation of Elements

3 Board Chemistry previous year questions on General Principles and Processes of Isolation of Elements — options free on every question; 1 include the answer & explanation free, the rest unlock with PYQ Pass.

Q1 FREE PREVIEW
PYQ

The chemical composition of ’slag’ formed during the smelting process in the extraction of copper is:

a

\(C{u}_{2}O+FeS\)

b

\(FeSi{O}_{3}\)

c

\(CuFe{S}_{2}\)

d

\(C{u}_{2}S+FeO\)

✓ Correct answer: b)

\(FeSi{O}_{3}\)

Explanation

During the extraction of copper, iron is present in the ore as impurity (FeS). The ore together with a little coke and silica is smelted; FeS present as impurity in the ore is oxidized to iron oxide, which then reacts with silica to form fusible ferrous silicate which is removed as slag. \(2FeS+3{O}_{2}\to 2FeO+2S{O}_{2}\) \(FeO+Si{O}_{2}\to \underset{\left(Slag\right)}{FeSi{O}_{3}}\)

Q2
PYQ

Which one of the following statements is incorrect?

a

Boron and Indium can be purified by zone refining method.

b

Van- Arkel method is used to purify tungsten.

c

Cast iron is obtained by melting pig iron with scrap iron and coke using hot air blast.

d

The malleable iron is prepared from cast iron by oxidising impurities in a reverberatory furnace

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Q3
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The methods NOT involved in concentration of ore are
(A) Liquation
(B) Leaching
(C) Electrolysis
(D) Hydraulic washing
(E) Froth floatation

Choose the correct answer from the options given below:

a

B, D and C only

b

C, D and E only

c

A and C only

d

B, D and E only

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