Class 11 chemistry MCQs with answers are provided here for the chapter States of Matter. These MCQs are based on the CBSE board curriculum and correspond to the most recent Class 11 chemistry syllabus. By practising these Class 11 Multiple choice questions, students will be able to quickly review all of the ideas covered in the chapter and prepare for the Class 11 Annual examinations as well as other entrance exams such as NEET and JEE.
Class 11 Chemistry States of Matter MCQs With Answer
Q1. Thermal energy is directly proportional to the:
- Volume of the substance.
- Mass of the substance.
- Temperature of the substance.
- Both (a) and (b)
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Ans: 3. Temperature of the substance.
Explanation:
Thermal energy is directly proportional to the temperature of the substance.
Q2. Dipole-dipole interaction is stronger than the London forces but is weaker than ion-ion interaction because:
- Only partial charges are involved.
- Total charges are involved.
- Charge of more electronegative part is involve.
- None of the above.
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Ans: 1. Only partial charges are involved.
Explanation:
It is because only partial charges are involved in dipole-dipole interaction. e.g. HCl molecules.
Q3. Which of the following property of water can be used to explain the spherical shape of rain droplets?
- Viscosity.
- Surface tension.
- Critical phenomena.
- Pressure.
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Ans: 2. Surface tension.
Explanation:
Due to surface tension, the surface of the water drops is under tension and tends to take a spherical shape to reduce the tension.
Q5. How does the surface tension of a liquid vary with increase in temperature?
- Remains same.
- Decreases.
- Increases.
- No regular pattern is followed.
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Ans: 2. Decrease.
Explanation:
The surface tension of a liquid decreases with increase in temperature due to less forces of attraction between the molecules.
Q6. The condition of free vaporisation throughout the liquid is called:
- Boiling.
- Melting.
- Freezing.
- Condensation
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Explanation:
Vaporisation can occur throughout the bulk of the liquid and vapours expand freely into surroundings. The condition of free
vaporisation throughout the liquid is called ‘boiling’.
Q7. The interaction energy of London force is inversely proportional to sixth power of the distance between two
interacting particles but their magnitude depends upon:
- Charge of interacting particles.
- Mass of interacting particles.
- Polarisability of interacting particles.
- Strength of permanent dipoles in the particles.
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Ans: 3. Polarisability of interacting particles.
Q8. What will be the minimum pressure required to compress 2L of gas at 1bar to 1L at 25°C?
- 1bar
- 2bar
- 4bar
- 6bar
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Ans: 2. 2bar
Q9. ‘At constant temperature, the pressure of a fixed amount of gas varies inversely with its volume’. This law is
known as:
- Charle’s law.
- Boyle’s law.
- Gay Lussac’s law.
- Dalton’s law
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Ans: 2. Boyle’s law.
Q10. As the temperature increases, average kinetic energy of molecules increases. What would be the effect of
increase of temperature on pressure provided the volume is constant?
- Increases.
- Decreases.
- Remains same.
- Becomes half.
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Ans: 1. Increases.
Explanation:
At constant volume, as the temperature is increased, pressure also increases.
Q11. Which of the following statements is correct?
- Evaporation occurs only at the surface.
- Evaporation takes place at all temperatures.
- Both (a) and (b) are correct.
- None of the above.
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Ans: 3. Both (a) and (b) are correct.
Q12. In kinetic molecular theory, it is assumed that average kinetic energy of the gaseous molecules is directly
proportional to the:
- Absolute pressure.
- Absolute volume.
- Absolute temperature.
- None of these.
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Ans: 3. Absolute temperature.
Explanation:
In kinetic molecular theory, it is assumed that average kinetic energy of the gaseous molecules is directly proportional to the absolute
temperature.
Q13. The total energy of the gaseous molecules before and after the collision remains same because:
- Collisions of gaseous molecules are perfectly elastic.
- Gases are highly compressible.
- Both (a) and (b).
- None of the above.
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Ans: 1. Collisions of gaseous molecules are perfectly elastic.
Q14. London or dispersion force is a/ an:
- Attractive force that acts between two temporary dipoles.
- Attractive force that acts between two permanent dipoles.
- Repulsive force that acts between two permanent dipoles.
- Repulsive force that acts between two temporary dipoles.
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Ans: 1. Attractive force that acts between two temporary dipoles.
Explanation:
Force of attraction acting between two temporary dipoles is known as London force.
Q15. The energy required to increase the surface area of the liquid by one unit is defined as:
- Surface energy.
- Potential energy.
- Free energy.
- Molecular energy.
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Ans: 1. Surface energy.
Explanation:
The energy required to increase the surface area of the liquid by one unit is called surface energy.
Q16. The negative deviation from ideal behaviour means that the:
- Value of pV decreases with decrease in pressure.
- Value of pV decreases with increase in pressure.
- Value of pV increases with increase in pressure.
- Value of pV remains constant with increase in pressure.
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Ans: 2. Value of pV decreases with increase in pressure.
Explanation:
The negative deviation from an ideal behaviour means that the value of pV decreases with increase in pressure
Q17. Maximum deviation from ideal gas is expected from:
- CH4
- NH3
- H2
- N2
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Ans: 2. NH3
Explanation:
Shows maximum deviation due to higher value of `a’ (intermolecular forces of attraction).
Q18. The type of attractive forces operating between the polar molecules having permanent dipole and the molecules
lacking permanent dipole is:
- Dipole-dipole.
- London forces.
- Dipole-induced dipole.
- H-bonding.
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Ans: 3. Dipole-induced dipole.
Q19. At 1atm pressure the boiling temperature is called normal boiling point and if pressure is 1bar then the boiling
point of the liquid is called:
- Normal boiling point.
- Standard boiling point.
- Critical boiling point.
- None of the above.
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Ans: 2. Standard boiling point.
Q20. Which of the following changes decrease the vapour pressure of water kept in a sealed vessel?
- Decreasing the quantity of water.
- Adding salt to water.
- Decreasing the volume of the vessel to one-half.
- Decreasing the temperature of water.
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Ans: 2. Adding salt to water.
- 4. Decreasing the temperature of water.
- Explanation:
Vapor pressure does not depend upon the quantity of water or size of the vessel. It decreases on adding salt to water or decreasing
the temperature of water.
Q21. Under which of the following two conditions applied together, a gas deviates most from the ideal behaviour
- Low pressure.
- High pressure.
- Low temperature.
- High temperature.
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Ans: 2. High pressure.
- 3. Low temperature.
- Explanation:
A gas which obeys the ideal gas equation, p V = nRT under all conditions of temperature and pressure is called an ‘ideal gas’.
However, there is no gas which obeys the ideal gas equation under all conditions of temperature and pressure. Hence, the concept of
ideal gas is only theoretical or hypothetical. The gases are found to obey the gas laws fairly well when the pressure is low or the
temperature is high.
Q22. The force acting per unit length perpendicular to the line drawn on the surface of liquid and its SI unit
respectively are:
- Gravitational force, Newton.
- Surface tension, Nm .
- Surface energy, Joule.
- None of the above.
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Ans: 2. Surface tension, Nm-1
Q23. Which of the following statements indicates that law of multiple proportion is being followed.
- Sample of carbon dioxide taken from any source will always have carbon and oxygen in the ratio 1 : 2.
- Carbon forms two oxides namely CO and CO, where masses of oxygen which combine with fixed mass of
carbon are in the simple ratio 2 : 1. - When magnesium burns in oxygen, the amount of magnesium taken for the reaction is equal to the amount
of magnesium in magnesium oxide formed. - At constant temperature and pressure 200mL of hydrogen will combine with 100mL oxygen to produce
200mL of water vapour.
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Ans: 2. Carbon forms two oxides namely CO and CO, where masses of oxygen which combine with fixed mass of carbon are in the simple
ratio 2 : 1.
Q24. “The total pressure exerted by the mixture of non-reactive gases is equal to the sum of the partial pressures of
individual gases”. Above statement represents the:
- Dalton’s law of partial pressure.
- Avogadro’s law.
- Graham’s law of diffusion.
- None of the above.
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Ans: 1. Dalton’s law of partial pressure.
Q25. The value of Z for real gases below Boyle’s temperature initially:
- Increases.
- Decreases.
- Remain same.
- Increases then decreases
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Ans: 2. Decreases.
Explanation:
Below Boyle’s temperature, real gases first show decrease in Z value with increasing pressure, which reaches a minimum value.
Q26. If the ratio of masses of SO and O gases confined in a vessel is 1 : 1, then the ratio of their partial pressure
would be:
- 5 : 2
- 2 : 5
- 2 : 1
- 1 : 2
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Ans: 2. 2 : 5
Q27. Which of the following is a correct statement?
- Surface tension of a liquid decreases with increase in temperature.
- Vapour pressure of a liquid decreases with increase in temperature.
- Viscosity of a liquid decreases with decrease in temperature.
- In gravity free environments, droplets of a liquid on flat surface are slightly flattened.
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Ans: 1. Surface tension of a liquid decreases with increase in temperature.
Explanation:
Surface tension of a liquid decreases with increase in temperature where as vapour pressure of Iiquid increases with increase in
temperature. Viscosity of a liquid decreases on increasing the temperature.
Q28. The strong intermolecular forces between molecules hold them together and resist the movement of layers past
one another. This property of liquid is called:
- Surface tension.
- Viscosity.
- Relative velocity.
- Critical volume.
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Ans: 2. Viscosity.
Q29. A person living in Shimla observed that cooking food without using pressure cooker takes more time. The reason
for this observation is that at high altitude:
- Pressure increases.
- Temperature decreases.
- Pressure decreases.
- Temperature increases.
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Ans: 3. Pressure decreases.
Explanation:
At high altitudes, pressure is low. Hence, boiling takes place at lower temperature and therefore, cooking takes more time. In pressure
cooker, pressure is high and hence boiling point increases.
Q30. Increase in kinetic energy can overcome intermolecular forces of attraction. How will the viscosity of liquid be
affected by the increase in temperature?
- Increase.
- No effect.
- Decrease.
- No regular pattern will be followed.
Click To View The Answer
Ans: 3. Decrease.
Explanation:
Intermolecular force of liquid decreases with increase in temperature, hence viscosity of liquid also decreases. However, some
exceptions are there like liquid proteins and liquid sulphur.