General Science Chemistry MCQs
Chemistry Objective (Multiple Choice) General Knowledge Questions & Answers for SSC-CGL, UPPSC, UPSC, NDA, CDS and UPSC Civil Services Prelims Examination
61. Which of the following sub-atomic particle accompanies an electron emission in Beta–decay?
[A] antineutrino
[B] neutrino
[C] proton
[D] None of the above
Show Answer
Correct Answer: A [antineutrino]
Notes:
The emission of electron in β−decay is accompanied by the emission of an antineutrino (ν ) and in β+ decay, a neutrino (ν) is generated.
62. What is the multiplication factor when the nuclear reactor is said to be critical?
Show Answer
Correct Answer: B [1]
Notes:
The multiplication factor is the measure of the growth rate of the neutrons in the reactor. For K = 1, the operation of the reactor is said to be critical.
63. Which of the following represents the reaction of Calcium oxide and water to form Slaked lime?
[A] Displacement reaction
[B] Combination reaction
[C] Double Displacement reaction
[D] None
Show Answer
Correct Answer: B [Combination reaction]
Notes:
A reaction in which a single product is formed from two or more reactants is known as a combination reaction. For example: calcium oxide and water combine to form a single product, slaked lime or calcium hydroxide.
64. Which of the following reactions take place when iron nail in a copper sulphate solution becomes brownish in colour?
[A] Decomposition reaction
[B] Displacement reaction
[C] Double Displacement reaction
[D] None of the above
Show Answer
Correct Answer: B [Displacement reaction]
Notes:
Iron nail in the Copper Sulphate solution become brownish in colour and the blue colour of copper sulphate solution fade. This happens because iron has displaced or removed another element, copper, from copper sulphate solution. This reaction is known as displacement reaction.
65. Which of the following equation represents combination of Hydrogen gas with nitrogen to form ammonia?
[A] 2H2 + N –> NH3
[B] 2H + N3 –> NH3
[C] 3H2 + N2 –> 2NH3
[D] None of the above
Show Answer
Correct Answer: C [3H2 + N2 –> 2NH3]
Notes:
3H2 + N2 –> 2NH3 is the balance equation which represents combination of Hydrogen gas with nitrogen to form ammonia.
66. What is the sum of powers of the concentration of the reactants called as?
[A] Order of reaction
[B] Stage of reaction
[C] Zone of reaction
[D] None of the above
Show Answer
Correct Answer: A [Order of reaction]
Notes:
The sum of powers of the concentration of the reactants in the rate law expression is known as the order of that chemical reaction.
67. What is the order of the reaction which is independent of the concentration of reactants?
[A] Zero order
[B] First order
[C] Second order
[D] Third order
Show Answer
Correct Answer: A [Zero order]
Notes:
Order of a reaction can be 0, 1, 2, 3 and even a fraction. A zero order reaction means that the rate of reaction is independent of the concentration of reactants.
68. What happens to the effective nuclear charge as we move from left to right in the periodic table?
[A] It increases
[B] it decreases
[C] It remains constant
[D] It increases till 4th group then decreases
Show Answer
Correct Answer: A [It increases]
Notes:
The effective nuclear charge of an element increases as we move from left to right in the periodic table.
69. What is the general trend for electronegativity in a group of the periodic table as we move from top to bottom?
[A] It increases
[B] It decreases
[C] It remains constant
[D] None
Show Answer
Correct Answer: B [It decreases]
Notes:
Electronegativity generally increases across a period from left to right (say from lithium to fluorine) and decrease down a group (say from fluorine to astatine) in the periodic table.
70. In which of the following groups is Gold placed in the modern periodic table?
Show Answer
Correct Answer: C [11]
Notes:
Group 11 of the modern periodic table is a group of chemical elements in the periodic table, consisting of copper (Cu), silver (Ag), and gold (Au).
Advertisement
