Physics

Thermodynamics and Gas Laws

616 Questions

Thermodynamics and gas laws questions test the understanding of ideal gas behavior, work done during thermodynamic processes, and specific heat ratios. Key areas include isothermal, adiabatic, and isobaric expansions along with real gas deviations. These mathematical physics concepts are standard in engineering and general science competitive exams.

Ideal gas equationIsothermal and adiabatic processesThermodynamic workGas kinetic theoryReal gas behavior

Thermodynamics and Gas Laws Questions

Multiple choice

If Vg, Vl and Vs represent the speeds of sound in a gas, liquid and solid respectively, which of the following options is true?

  1. Vg > Vl > Vs

  2. Vl > Vs >Vg

  3. Vs > Vg > Vl

  4. Vs > Vl > Vg
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Sound travels fastest in solids (highest speed), then liquids, and slowest in gases. This is because sound speed depends on how closely particles are packed and how quickly they can transfer vibrations. Solids have the densest packing and strongest bonds, enabling fastest sound propagation.

Multiple choice

A large volume of a gas can be compressed into a small cylinder and transported easily. Which among the following characteristics justifies the statement?

  1. Large intermolecular spaces

  2. Strong intermolecular force of attraction

  3. Low kinetic energy

  4. Tightly packed particles
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The particles of gases possess large intermolecular spaces. That is why a large volume of a gas can be compressed into a small cylinder and transported easily.

Multiple choice

Which among the following justifies that a gas exerts pressure on the walls of the container?

  1. The particles have a weak force of attraction.

  2. The particles are continuously moving.

  3. The particles have negligible space between them.

  4. The particles have strong bonds of attraction.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In gaseous state, the particles move about randomly at high speed. Due to this random movement, the particles hit each other and also the walls of the container. The pressure exerted by the gas is because of this force exerted by the gas particles per unit area on the walls of the container.

Multiple choice

Which one of the following is not an intensive property in thermodynamics?

  1. Pressure

  2. Density

  3. Volume

  4. Temperature
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Intensive property is the property which depend only upon the nature of substance and are independent of the amount of the substance present in the sytem. Pressure, density, surface tension and temperature are intensive property but volume is not an intensive property.

Multiple choice

Why is it difficult to move your hand through a table, while it is easy to move your hand through air?

  1. Because particles are loosely packed in solid<font size="2"> state,</font> but are tightly packed in gase<font size="2">ous state</font>

  2. Because particles <font size="2">in</font> solid <font face="Arial" size="2"><font size="2">state</font></font> possess weak forces of attraction, but those in gase<font size="2">ous </font><font size="2"><font face="Arial" size="2"><font size="2">state</font></font></font> possess strong forces of attraction

  3. Because particles <font size="2">in</font> solid<font size="2"> </font><font size="2"><font face="Arial" size="2"><font size="2">state</font></font></font> have a negligible space in between them, but those in gase<font size="2">ous </font><font size="2"><font face="Arial" size="2"><font size="2">state</font></font></font> have a large space in between them

  4. Because particles in solid state possess high kinetic energy, but those in gaseous state possess low kinetic energy
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The constituent particles of solids are tightly packed and in the absence of inter-particle spaces no object can move through it. Movement through  the gaseous state of matter is possible due to the large inter-molecular spaces.

Multiple choice

For the equilibrium established between butane and isobutane, if the volume of the container is halved, the equilibrium will

  1. shift in forward direction

  2. not change

  3. shift in backward direction

  4. shift randomly
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

This option is correct and can be explained as follows: The equilibrium constant for the reaction in the given question is given ask  =  [Butane]/[Isobutane].   However on decreasing the volume of the container the individual concentration of butane and isobutane increases but the overall change in equilibrium constant will be zero as the increase in concentrations of reactant and products will be cancelled.

Multiple choice

If an ideal gas is used and the quantity of gas stays constant, then the increase in energy is proportional to an increase in temperature and pressure in an

  1. adiabatic process

  2. isobaric process

  3. isochoric process

  4. isentropic process

  5. isothermal process
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

An isochoric process, also called a constant-volume process, an isovolumetric process, or an isometric process, is a thermodynamic process during which the volume of the closed system undergoing such a process remains constant.

Multiple choice

Which of the following statements is/are false?

a. The molecules in water are tightly packed, having no spaces between them. b. The force of attraction is maximum in the particles of solid matter and minimum in the particles of gaseous matter. c. The molecules in a gas exert negligible small forces on each other, except during collisions.

  1. Only a

  2. Only a and b

  3. Only b

  4. Only b and c

  5. Only c
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This is the correct option as this statement is false. The molecules in water are not tightly packed; they have spaces between them.

Multiple choice

Which of the following statements are not false?

  1. The protecting power of lyophilic colloidal sol is expressed in terms of gold number.
  2. Rate of physical adsorption increase with decrease in temperature.
  3. In Freundlich Adsorption isotherm, the value of 1/n is 0 in case of physical adsorption and 1 in case of chemisorptions.
  4. In Langmuir's model of adsorption of a gas on a solid surface the mass of gas striking a given area of surface is independent of the pressure of the gas.

  1. Only 1 and 2

  2. Only 1, 2 and 3

  3. Only 1 and 4

  4. Only 2 and 3

  5. Only 3 and 4
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Yes, both the statements are true. Hence, it is the correct answer.

Multiple choice

Which of the following statements is/are false?

a. The Brownian motion can be observed in gases. b. Due to fluidity, liquids and gases change their shapes readily. c. The movement of different particles among each other on their own, so that they get mixed uniformly is called condensation.

  1. Only a

  2. Both a and b

  3. Only b

  4. Both b and c

  5. Only c
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

This is the correct option as this statement is false. The movement of different particles among each other on their own so that they get mixed uniformly is called diffusion.

Multiple choice

Which of the following statements is/are false?

a. The force of attraction is minimum in the particles of solid matter and maximum in the particles of gaseous matter. b. The pressure exerted by the gas on the walls of its container is due to the collision of the fast moving gas particles against the walls of the container. c. A sponge is considered to be a solid because its compressibility is due to the presence of minute pores in it, which are filled with air.

  1. Only a

  2. Both a and b

  3. Only b

  4. Both b and c

  5. Only c
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This is the correct option as this statement is false. The force of attraction is maximum in the particles of solid matter and minimum in the particles of gaseous matter.