Chemistry: Physical Chemistry: UPSC Previous Year Questions (Science and Technology)
3 previous year UPSC Prelims questions on Chemistry: Physical Chemistry (Science and Technology). Choose an option to see the answer and explanation.
Explanations state facts as of the year each question was asked; words like “recently” refer to that year.
Showing 1–3 of 3 questions
UPSC 2003Science and Technology · Chemistry: Physical Chemistry
Q1. With reference to ionic compounds, consider the following statements: 1. Ionic compounds are insoluble in alcohol. 2. Ionic compounds in the solid state are good conductors of electricity. Which of these statements is/are correct?
Explanation
Ionic compounds are chemical compounds composed of positively and negatively charged ions held together by strong electrostatic forces of attraction.
Statement 1 is correct: Ionic compounds generally dissolve in water due to its high polarity, but alcohols are less polar compared to water, which makes most ionic compounds insoluble in alcohol.
Statement 2 is incorrect: In the solid state, the ions in ionic compounds are fixed in a rigid lattice structure and cannot move freely, which prevents the conduction of electricity.
UPSC 2003Science and Technology · Chemistry: Physical Chemistry
Q2. Regarding the atom of a chemical element, the magnetic quantum number refers to:
Explanation
Option (a) is correct: The magnetic quantum number of an element specifies the orientation of an orbital in space relative to an external magnetic field. It determines the number of orbitals and their spatial orientation within a given subshell (defined by the azimuthal quantum number, l). Options (b), (c) and (d) are incorrect: Shape is determined by the azimuthal quantum number; Size is determined by the principal quantum number; Spin is determined by the spin quantum number, which specifies the spin orientation of the electron.
UPSC 2003Science and Technology · Chemistry: Physical Chemistry
Q3. Which one of the following statements is correct?
Explanation
Option (a) is correct: Liquid sodium is used as a coolant in certain types of nuclear reactors, particularly fast breeder reactors. Sodium is an effective coolant because of its high thermal conductivity and low neutron absorption properties, which are ideal for cooling the reactor core. Options (b), (c) and (d) are incorrect:
Dental amalgams are typically made of silver, mercury, and other metals. Calcium carbonate is not a must-include ingredient in toothpastes. Though it is sometimes used in toothpaste as an abrasive that helps remove plaque, stains, and debris from teeth. Bordeaux mixture is made from copper sulfate and lime (calcium hydroxide). It is used as a fungicide and pesticide in agriculture to prevent fungal diseases like downy mildew in crops. Zinc amalgam is not commonly used in dental fillings, although zinc oxide is sometimes used in dental cements and temporary fillings.
Answer key for these questions
Q
UPSC year
Correct answer
1
2003
(a) Only 1
2
2003
(a) Orientation
3
2003
(a) Liquid sodium is employed as a coolant in nuclear reactors.
Frequently asked questions
How many previous year UPSC questions are there on Chemistry: Physical Chemistry?
This page covers 3 previous year UPSC Prelims GS Paper-I questions on Chemistry: Physical Chemistry (Science and Technology), asked from 1996 to 2009. Each has the correct answer and an explanation.
How should I use previous year UPSC questions for Prelims?
Attempt each question first, then open the answer and read the explanation for every option. Repeat by chapter, and track which statements UPSC reuses across years. Previous year questions show the exam pattern and difficulty level.
Which years are covered for Chemistry: Physical Chemistry?
Questions on Chemistry: Physical Chemistry (Science and Technology) are available for 8 years, from 1996 to 2009. Use the Year filter to practise a single paper.
