Chemistry · Chapter 5 of 11

States of Matter: BPSC & UPPCS Prelims PYQs

9 previous-year questions on States of Matter. Each one opens to its answer and explanation.

1. 1. UPPSC Prelims 2025

   Which of the following gases is/are lighter than air?
   1. Hydrogen chloride
   2. Sulfur dioxide
   3. Helium
   Select the correct answer from the code given below:

   1. AOnly 1
   2. B2 and 3
   3. COnly 3
   4. D1 and 2
   Answer and explanation →

2. 2. 70th BPSC Prelims 2024 Asked again

   Which of the following represents the suitable condition for the liquefaction of gases?

   1. ALow temperature, high pressure
   2. BLow temperature, low pressure
   3. CHigh temperature, high pressure
   4. DHigh temperature, low pressure
   Answer and explanation →

3. 3. 70th BPSC Prelims 2024

   For two liquids A and B to form an ideal solution

   1. AEntropy of mixing must be zero
   2. BFree energy of mixing should be zero
   3. CEnthalpy of mixing should be zero
   4. DNone of the above
   Answer and explanation →

4. 4. UPPSC Prelims 2024 Asked again

   Milk is an example of:

   1. ASol
   2. BAerosol
   3. CFoam
   4. DEmulsion
   Answer and explanation →

5. 5. 68th BPSC Prelims 2023

   A form of matter has no fixed shape but it has a fixed volume. An example of this form of matter is

   1. ACarbon steel
   2. BKrypton
   3. CKerosene
   4. DMore than one of the above
   5. ENone of the above
   Answer and explanation →

6. 6. 68th BPSC Prelims 2023

   Which of the following statements about diamond and graphite is true?

   1. AThey have same electrical conductivity.
   2. BThey have same crystal structure.
   3. CThey have same degree of hardness.
   4. DMore than one of the above
   5. ENone of the above
   Answer and explanation →

7. 7. 67th BPSC Prelims 2022

   Consider the following statements:
   1. Addition of salt to pure water increases the boiling point of water and decreases the freezing point of water.
   2. When methyl alcohol is added to water boiling point of water decreases.
   Which of the above statements is/are correct?

   1. A1 only
   2. B2 only
   3. CBoth 1 and 2
   4. DSalt and methyl alcohol are same in behaviour
   5. ENone of the above/More than one of the above
   Answer and explanation →

8. 8. 67th BPSC Prelims 2022

   Which law states that, under the same conditions of temperature and pressure, equal volumes of all gases contain an equal number of molecules?

   1. AGraham's law
   2. BPascal's law
   3. CAvogadro's law
   4. DCoriolis effect
   5. ENone of the above/More than one of the above
   Answer and explanation →

9. 9. UPPSC Prelims 2019 Asked again

   A sample of any of the following substances disappears after sometime when exposed to air like camphor, naphthalene or dry ice. This phenomenon is called

   1. ASublimation
   2. BEvaporation
   3. CDiffusion
   4. DRadiation
   Answer and explanation →