The purification of alumina is called

• Baeyer's process

• Bosch process

• Castuer process

• Hoop's process.

372.

The element which is the most abundant in the earth crust is

• O

• S

• Al

• H

Reagent used to extract silver from Ag₂S is :

• NaCN

• NaCN in presence of O₂

• NaCl

• AgNO₃

Given below, catalyst and corresponding process/ reaction are matched. The mismatch is

• [RhCl(PPh₃)₂] : Hydrogenation

• TiCl₄+ Al(C₂H₅)₃ : Polymerization

• V₂O₅ : Haber-Bosch process

• nickel : Hydrogenation.

Which of the following is not an ore of magnesium ?

• Magnesite

• Dolomite

• Gypsum

• Carnalite

In Mc Arthur Forest method , silver is extracted from the solution of Na[Ag(CN)₂] by the use of :

• Fe

• Mg

• Cu

• Zn

Which of the following dissolves in hot conc. NaOH solution ?

• Fe

• Zn

• Cn

• Ag

Assertion : Extraction of iron metal from iron oxide ore is carried out by heating with coke.

Reason : The reaction Fe₂O_{3 (s)} → Fe _(s) + $\frac{3}{2}$O_{2 (g)} is a spontaneous process.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

The iron, obtained from blast furnace is :

• pig iron

• cast iron

• wrought iron

• steel

Which of the following is not an ore of iron ?

• Limonite

• Caniterite

• Magnetite

• None of these