In the extraction of chlorine by electrolysis of brine.......

1

(a)

oxidation of Cl^- ions to chlorine gas occurs

(b)

reduction of Cl^- ions to chlorine gas occurs

(c)

for overall reaction \(\Delta\)G⁰ has negative value

(d)

a displacement reaction takes place

When copper ore is mixed with silica,in a reverberatory furnace,copper matte is produced.The copper matte contains.....

1

(a)

sulphides of copper (II) and iron (II)

(b)

sulphides of copper (II) and iron (III)

(c)

sulphides of copper (I) and iron (II)

(d)

sulphides of copper (I) and iron (III)

Which of the following reactions is an exam[le of autoreduction?

1

(a)

Fe₃O₄+4CO\(\longrightarrow\)3Fe+4CO₂

(b)

Cu₂O+C\(\longrightarrow\)2Cu+CO

(c)

Cu²⁺(aq)+Fe(s)\(\longrightarrow\)Cu(s)+Fe²⁺(aq)

(d)

Cu₂O+\(1\over2\)Cu₂S\(\longrightarrow\)3Cu+\(1\over2\)SO₂

A number of elements are available in earth,s crust but most abundant elements are __________________.

1

(a)

Al and Fe

(b)

Al and Cu

(c)

Fe and Cu

(d)

Cu and Ag

Zone refining is based on the principle that.....

1

(a)

impurities of low boiling metals can be separated by distillation

(b)

impurities are more soluble in molten metal than in solid metal

(c)

different components of a mixture are differently adsorbed on an adsorbent

(d)

vapours of volatile compound can be decomposed in pure metal