chemistry

GENERAL PRINCIPLES AND PROCESSES OF ISOLATION OF ELEMENTS EAMCET MCQ’S

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

(i) oxidation of Cl– ion to chlorine gas occurs.

(ii) reduction of Cl– ion to chlorine gas occurs.

(iii) For overall reaction ΔGV has negative value.

(iv) a displacement reaction takes place.

2. When copper ore is mixed with silica, in a reverberatory furnace copper matte

is produced. The copper matte contains ____________.

(i) sulphides of copper (II) and iron (II)

(ii) sulphides of copper (II) and iron (III)

(iii) sulphides of copper (I) and iron (II)

(iv) sulphides of copper (I) and iron (III)

3. A number of elements are available in earth’s crust but most abundant

elements are ____________.

(i) Al and Fe

(ii) Al and Cu

(iii) Fe and Cu

(iv) Cu and Ag

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

(i) impurities of low boiling metals can be separated by distillation.

(ii) impurities are more soluble in molten metal than in solid metal.

(iii) different components of a mixture are differently adsorbed on an adosrbent.

(iv) vapours of volatile compound can be decomposed in pure metal.

5. In the extraction of copper from its sulphide ore, the metal is formed by the

reduction of Cu2O with

(i) FeS

(ii) CO

(iii) Cu2S

(iv) SO2

6. In the metallurgy of aluminium ________________.

(i) Al3+ is oxidised to Al (s).

(ii) graphide anode is oxidised to carbon monoxide and carbon dioxide.

(iii) oxidation state of oxygen changes in the reaction at anode.

(iv) oxidation state of oxygen changes in the overall reaction involved in the

process.

7. Electrolytic refining is used to purify which of the following metals?

(i) Cu and Zn

(ii) Ge and Si

(iii) Zr and Ti

(iv) Zn and Hg

8. Extraction of gold and silver involves leaching the metal with CN – ion. The

metal is recovered by ________________.

(i) displacement of metal by some other metal from the complex ion.

(ii) roasting of metal complex.

(iii) calcination followed by roasting.

(iv) thermal decomposition of metal complex

9. Below point ‘A’ FeO can ______________.

(i) be reduced by carbon monoxide only.

(ii) be reduced by both carbon monoxide and carbon.

(iii) be reduced by carbon only.

(iv) not be reduced by both carbon and carbon monoxide.

10. For the reduction of FeO at the temperature corresponding to point D, which

of the following statements is correct?

(i) ΔG value for the overall reduction reaction with carbon monoxide is

zero.

(ii) ΔG value for the overall reduction reaction with a mixture of 1 mol carbon

and 1 mol oxygen is positive.

(iii) ΔG value for the overall reduction reaction with a mixture of 2 mol carbon

and 1 mol oxygen will be positive.

(iv) ΔG value for the overall reduction reaction with carbon monoxide is

negative.