The first element of rare earth metal is
Match Column I with Column II .
Column – Column II
A . Copper 1 . Corundum, bauxite
B . Iron 2 . Malachite, azurite
C . Lead 3 . Galena, lanarkite
D . Aluminium 4 . Haematite, limonite
(A) 2 4 3 1
(B) 4 3 1 2
(C) 3 1 2 4
(D) 1 2 4 3
Chemical leaching is useful in the concentration of
(A) copper pyrites
When ammonium chloride is dissolved in water, the solution becomes cold. The change is
(C) super cooling
(D) None of the above
A conductivity cell is Platonized
(A) to prolong its service
(B) to avoid temperature effect
(C) to avoid polarization effect
(D) None of the above
MatchColumn I with Column II .
Column I -Column II
A . Most reactive alkali metal active non-metal 1 . F2
B . Chemically most density 2 . Cs
C . Metal with maximum 3 . Hg
D . Transition metal is in liquid state 4 . Os
(A) 4 3 2 1
(B) 1 4 3 2
(C) 2 1 4 3
(D) 3 2 1 4
In blast furnace, iron oxide is reduced by
Assertion (A) Metals are good conductors of heat.
Reason (R) On burning, metals react with oxygen to produce metal oxides.
(A) Both A and R are true and R is the correct explanation of A.
(B) Both A and R are true but R is not the correct explanation of A:
(C) A is true but R is false.
(D) A is false but R is true.
The order of appearance of the following with increasing temperature during the refining of crude oil is
(A) gasoline, diesel, kerosene
(B) gasoline, kerosene, diesel
(C) diesel, gasoline, kerosene
(D) kerosene, gasoline, diesel
Assertion (A) Copper metal with HCI liberates hydrogen.
Reason (R) Hydrogen is present above Cu in the reactivity series.
(A) Both A and R are individually true and R is the correct explanation of A.
(B) Both A and R are individually true, but R is not the correct explanation of A.
(C) A is true, but R is false. .
(D) A is false, but R is true.
Which one among the following is the correct order of reactivity of the elements?
(A) Cu > Mg > Zn > Na
(B) Na > Zn > Mg > Cu
(C) Cu > Zn > Mg > Na
(D) Na > Mg > Zn > Cu
Consider the following statements
1 . In electro-refining, the impure metal is made anode.
2 . in metallurgy, flux is a substance used to convert fusible impurities to infusible impurities.
3 . Copper is extracted by thermal reduction process.
Which of the above is/are true?
(A) Only 1
(B) 1 and 3
(C) 2 and 3
(D) 1, 2 and 3
Blister copper is about
(A) 60% Cu
(B) 90% Cu
(C) 98% Cu
(D) 100% Cu
Which statement is correct about the fusion of copper?
(A) A solid is formed
(B) Heat is required
(C) The process is exothermic
(D) Heat is released
Which one of the following pairs of materials serves as electrodes in chargeable batteries commonly used in devices such as torchlight’s, electric shavers etc?
(A) Nickel and cadmium
(B) Zinc and carbon
(C) Lead peroxide and lead
(D) Iron and cadmium
The elements of a group in the Periodic Table
(A) have similar chemical properties
(B) have consecutive atomic numbers
(C) are isobars
(D) are isotopes
Which one of the following materials is very hard and very ductile?
(C) Cast iron