Current Affairs 2021 PDF

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IAS/IPS Prelims Chemistry - General Knowledge Questions and Answers for UPSC Exam | Page-3

Questions
21 Mixture of which one of the following pairs of gases is the cause of occurrence of most of the explosions in mines ?
A methane and air
B oxygen and acetylene
C hydrogen and oxygen
D carbon dioxide with ethane

Answer: Option [A]
22 In an atom, the order of filling up of the orbitals is governed by
A Hund’s rule
B Aufbau’s principle
C Heisenberg’s uncertainly principle
D Pauli’s exclusion principle

Answer: Option [B]
23 In a dry cell (battery), which of the following are used as electrolytes ?
A Ammonium chloride and Calcium chloride
B Magnesium chloride and Zinc chloride
C Sodium chloride and Calcium chloride
D Ammonium chloride and Zinc chloride

Answer: Option [D]
24 Which one of the following is a mixed fertilizer ?
A CAN
B Urea
C NPK
D Ammonium sulphate

Answer: Option [C]
25 Consider the following statements: Cook is one of the materials of the charge added to blast furnace for the production of steel / iron. Its function is to

Of these statements

I. act as the reducing agent
II. remove silica associated with the iron ore
III. function as fuel ; to supply heat
IV. act as an oxidizing agent

A I and II are correct
B II and IV are correct
C I and III are correct
D III and IV are correct

Answer: Option [C]
26 An aqueous solution of copper sulphate is acidic in nature because the salt undergoes
A dialysis
B hydrolysis
C photolysis
D electrolysis

Answer: Option [B]
27 Which are the materials generally employed as solder in soldering operations in electronics ?
A Lead and tin
B Iron and tin
C Aluminium and iron
D Aluminium and lead

Answer: Option [A]
28 What are Rubies and Sapphires chemically known as ?
A Lead tetroxide
B Silicon dioxide
C Boron nitride
D Aluminium oxide

Answer: Option [D]
29 Which one of the following is another name of RDX ?
A Cyclonite
B Cyclohexane
C Cyanohydrin
D Dextran

Answer: Option [A]
30 Which one of the following is used as an explosive ?
A Graphite
B Nitroglycerine
C Mercuric oxide
D Phosphorus trichloride

Answer: Option [B]

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