TRANSITION ELEMENT QUIZ-8

Q1. The methods chiefly used for the extraction of lead and tin from their ores are respectively

•  Cyanide process and carbon reduction
•  carbon reduction and self reduction
•  Self reduction and electrolytic reduction
•  Self reduction and carbon reduction

Solution
The methods chiefly used for the extraction of lead and tin from their ores are respectively self reduction and carbon reduction. (Because the process of heating the ore strongly in the presence of excess of air is called roasting. It is mainly used in case of sulphide ores and the process of extracting a metal by fusion of the oxide ore with carbon is known as smelting.)

Q2.A compound is yellow when hot and white when cold. The compound is :

•  Al_2 O_3
•  ZnO
•  PbO
•  CaO

Solution
ZnO possess this characteristics..

Q3.  Which of the following has got incompletely filled f-subshell?

•   Tantalum
•  Lawrencium
•  Lutetium
•  Gadolinium

Solution
Gadolinium (Z=64) [Xe] 4f^7,5d^1,6s^2 Lutetium(Z=71)[Xe] 4f^14,5d^1,6s^2 Lawrencium(Z=103)[Rn] 5f^14,6d^1,7s^2 Tantalum(Z=73) [Xe]4f^14,5d^3,6s^2 Hence, gadolinium has got incompletely filled f-subshell .

Q4. Substance used in glazing pottery is:

•  Calome
•  Alum
•  ZnCl_2
•  ZnO

Solution
White vitriol is ZnSO_4.7H_2 O.

Q5.d-block elements generally form:

•  Interstitial hydrides
•  Salt-like hydrides
•  Metallic hydrides
•  Covalent hydrides

Solution
 A characteristic hydride formation by d-block elements

Q6. The temperature of the slag zone in the metallurgy of iron using blast furnace is

•  1200-1500°c
•  800-1000°c
• 400-700°c
•  1500-1600°c

Solution
The temperature of the slag zone in the metallurgy of iron using blast furnace is 800-1000°C.

Q7.In comparison to ferrous salts, ferric salts are:

•  None of these
•  Equally stable
•  More stable
•  Less stable

Solution
Fe^(3+) is more stable than Fe^(2+) because of half-filled nature

Q8.Cuprous chloride is obtained from cupric chloride:

•  By passing H_2 over CuCl_2
•  By heating cupric chloride with conc. HCl and copper turnings
•  By heating cupric chloride with chlorine
•  By the electrolysis of cupric chloride containing HCl

Solution

Q9.During the extraction of copper, the impurity (FeS) is removed as slag by mixing the contaminated copper ore with silica and coke. The molecular formula of slag is

•  FeSi (vapour)
•  FeSi (solid)
•  The Majority Leader in the Lok SabhaFe_2 O_3
•  FeSiO_3

Solution
During the extraction of copper, the impurity (FeS) is removed as slag by mixing the contaminated copper ore with silica and coke. 2FeS+3O_2 ⟶2FeO+2SO_2 FeO+SiO_2 ⟶FeSiO_3 silica ferrous silicate (slag)

Q10. Which metal does not form amalgam?

•  Cu
•  Fe
•  Ag
• Zn

Solution
Fe and Pt do not form amalgam with Hg.