Explore topic-wise InterviewSolutions in .

(i) – (c) 

(ii) – (d) 

(iii) – (a) 

(iv) – (b)

1. The property due to which a substance can be hammered (or rolled) into a thin sheet without cracking is called malleability. 

2. Metals are malleable. Thus, a metal can be hammered to form a thin sheet.

(1) In the froth floatation process, in a tank water, ore and an oil are mixed. When air is bubbled through the mixture the oil forms froth.

(2) The mineral particles are wetted by the oil and float on the surface.

(3) The gangue particles are wetted by water and settle down. Hence, the ore can be concentrated. 

Hence, air is bubbled through the mixture in froth floatation process.

(1) Silver is a soft metal and wears off on constant usage particularly due to abrasion. Silver amalgam is an alloy of silver with mercury.

(2) It is a hard substance. It is nontoxic. Besides these properties it is a lustrous shining substance. It melts at a comparatively low temperature and can therefore conveniently fill in the cavities. 

Hence, silver amalgam is used for filling dental cavities.

i. Tungsten has the highest melting point.

ii. Mercury and galium are two metals in the liquid state at room temperature.

iii. Diamond is the hardest natural substance.

iv. The naturally occurring compounds of metals along with other impurities are known as minerals.

v. The minerals from which metals are extracted profitably and conveniently are called ores.

1. Ionic compounds are solids and hard due to strong electrostatic force of attraction between oppositely charged ions. 

2. They are generally brittle. When pressure is applied they break into pieces. 

3. They have high melting and boiling points, due to intermolecular force of attraction is high in ionic compounds. 

4. They are soluble in water and insoluble in solvents such as kerosene and petrol. 

5. Ionic compounds cannot conduct electricity when in solid state, they are electrically neutral. They conduct electricity in the molten state and also in an aqueous solution.

The cation and anion being oppositely charged, there is an electrostatic force of attraction between them, this force of attraction between cation and anion is called the ionic bond.

A process in which a less reactive metal is coated on a more reactive metal by electrolysis is called electroplating.

Chromato means Colour and graphy means writing because the method was first used for separation of coloured substance. It is based on selective distribution of various constituents of a mixture between two phases, a stationary phase and a moving phase. The stationary phase can be either solid or liquid on solid support. 

The arrangement of metals in the increasing order of their activity:

Silver < Copper < Iron < Aluminium

 Ferrous alloys: It is an alloy having iron as one of the constituent, e.g., nickel, steel.

Non-ferrous alloys: An alloy that does not contain iron as one of its constituents, is called a non-ferrous alloy, e.g., brass. 

(a) Type metal is hard and expands on cooling and is therefore used for making types. 

(b) Duralumin, is light and strong therefore it is used in the construction of air-craft.

i. Zinc is obtained by the reduction of its oxide by carbon.

ii. Graphite is used as an anode during the electrolytic reduction of bauxite.

iii. Silver gets corroded due to hydrogen sulphide in air.

iv. Diamond is the hardest substance and has the highest melting and boiling points.

v. (d) all of these

vi. To show that zinc is more reactive than copper, the correct procedure is to prepare copper sulphate solution and dip a zinc strip in it.

vii. Iron is less reactive than aluminium.

viii. A solution of Al₂(SO₄)₃ in water is colourless.

ix. A solution of CuSO₄ in water is blue in colour.

x. A solution of FeSO₄ in water is green in colour.

(d) Galium

Reason:

Cu, Zn and Ag are purified by electrolytic refining while Ga is not.

Silica act as flux to remove basic impurities of FeO

FeO + SiO₂ → FeSiO₃

Cast iron is different from pig iron and is made by melting pig iron with scrap iron and coke using hot air blast. It has slightly lower carbon content (about 3%) and is extremely hard and brittle.

Wrought iron or malleable iron is the purest form of commercial iron and is prepared rom cast iron by oxidising impurities in a reverberatory furnace lined with haematite. This haematiteoxidises carbon to carbon monoxide: 

Fe₂O₃ + 3 C → 2 Fe + 3 CO whereas steel is an alloy of iron and carbon