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 chemistry states of matter: gaseous and liquid states gay lussac's law gas laws states of matter

To use Gay-Lussac's Law, which of the following needs to remain constant?

  1. Volume and the number of moles of a gas

  2. Pressure and temperature

  3. Temperature and the number of moles of a gas

  4. Pressure and the number of moles of a gas

  5. Temperature and volume
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

$P \propto T $
At constant volume and number of moles of a gas, the pressure is directly proportional to the absolute temperature.

Hence, option $A$ is correct.

Multiple choice applications of adsorption adsorption adsorption and colloids surface chemistry chemistry

Which of the following is most favourable for vander waals  adsorption?

  1. high pressure and high temperature

  2. low pressure and low temperature

  3. low pressure and high temperature

  4. high pressure and low temperature
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Physisorption is Vanderwaals adsorption, it occurs at high pressure and low temperature conditions.

Multiple choice conduction in metals and non-metals thermal energy transfers physics

It is required to double the pressure of a gas contained in steel cylinder by heating. If the initial temperature of the gas is ${ 27 }^{ 0 }C$, the temperature upto which it the gas is to be heated is 

  1. ${ 327 }^{ 0 }C$
  2. ${ 273 }^{ 0 }C$
  3. ${ 108}^{ 0 }C$
  4. ${ 54 }^{ 0 }C$
Reveal answer Fill a bubble to check yourself
C Correct answer
Multiple choice chemistry combustion structure of flame flame combustion, fuels and flame

In LPG cylinder, the gas is liquefied by ___________.

  1. increasing volume

  2. applying pressure

  3. increasing temperature

  4. none of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

LPG (Liquefied Petroleum Gas) is stored in cylinders under high pressure, which forces the gas molecules together to change their state from gaseous to liquid.

Multiple choice physics heat energy transfers heat energy heat, internal energy and work internal energy

How much heat energy in joules must be supplied to $14\ gms$ of nitrogen at room temperature to rise its temperature by $ 40^o C $ at constant pressure?
(Mol.wt.of $ N _2 = 28 gm , R = constant $)

  1. $50R$
  2. $60R$
  3. $70R$
  4. $80R$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Given,

Mass of nitrogen, $m=14gms$
Temperature, $T=40^0C$
Molecular weight of nitrogen, $M=28gms$
Now,
We know that,
Amount of heat supplied, $Q = n{C _p}\left( {dT} \right)$
No, of moles, $n = \frac{m}{M}$
$\therefore Q = \frac{m}{M}{C _p}dT$
$\begin{array}{l} =\frac { { 14 } }{ { 28 } } \times \frac { { 7R } }{ 2 } \times 40 \ =70R \end{array}$
Hence,
Option $C$ is correct answer.

Multiple choice biology water a precious resource water cycle earth's energy budget bio-geo chemical cycles in nature solar energy and its applications

What would be temperature of gaseous hydrocarbon in condensation?

  1. Higher temperature

  2. Lower temperature

  3. Normal temperature

  4. Extremely high temperature
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Condensation is the process where a gas turns into a liquid. This phase change requires the removal of heat, meaning the substance must be at a lower temperature than its boiling point to transition.

Multiple choice chemistry how far? how fast? collision theory collision theory of chemical reactions rate of chemical reaction

If X is the total number of collisions which a gas molecule registers with other molecules per unit time under particular conditions, then the collision frequency of the gas containing N molecules per unit volume is?

  1. X/N

  2. NX
  3. $2NX$
  4. $NX/2$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The collision frequency Z is related to the number of collisions per unit volume. For a gas with N molecules per unit volume, the collision frequency is given by Z = (sqrt(2) * pi * d^2 * v_avg * N^2) / 2. The standard expression for collision frequency per unit volume is proportional to N^2, but given the options and the definition of X, the factor of 1/2 accounts for double counting in binary collisions.

Multiple choice chemistry how far? how fast? collision theory collision theory of chemical reactions rate of chemical reaction

The number of collisions of Ar atoms with the walls of container per unit time?

  1. Increases when the temperature increases
  2. Remains the same when $CO _2$ is added to the container at constant temperature
  3. Increases when $CO _2$ is added to the container at constant temperature

  4. Decreases, when the average kinetic energy per molecule is decreased
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The number of collisions with the walls per unit time is proportional to the average speed of the molecules. Since average speed is proportional to the square root of temperature, increasing the temperature increases the collision frequency.

Multiple choice chemistry how far? how fast? collision theory collision theory of chemical reactions rate of chemical reaction

When the temperature of an ideal gas is increased at constant pressure?

  1. Collision number increases

  2. Collision frequency increases

  3. Mean free path increases

  4. Number of molecules per unit volume increases
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

When temperature increases at constant pressure, the volume must increase (Charles's Law). The number of molecules per unit volume (N/V) decreases. The collision number (collisions per molecule) is related to the frequency of collisions, which depends on density and speed.

Multiple choice chemistry study of compounds a. hydrogen chloride laboratory method of preparation of hydrochloric acid physical and chemical properties and uses of hydrochloric acid hydrogen chloride: occurrence, preparation, purification and identification

Observing the method of collection of the gas, what you can tell about the density of hydrogen chloride?

  1. A gas that is more dense than air

  2. A gas that is less dense than air

  3. A gas (liqued form ) that is less dense than air

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A gas that is more dense than air can be collected by downward delivery. Examples of gases that can be collected by this method are carbon dioxide, chlorine, HCl, sulphur dioxide.

Multiple choice physics heat and temperature anomalous expansion of water thermal expansion in solids, liquids and gases thermal expansion

Coefficient of real expansion

  1. Apparent increase in volume/original volume $\times$ rise in temperature
  2. True increase in volume/ original volume $\times$ rise in temperature

  3. Both

  4. None
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The true increase in the volume of liquid per unit original volume of liquid per degree rise in temperature is called coefficient of volume expansion.

Multiple choice physics behaviour of perfect gas and kinetic theory of gases mean free path law of equipartition of energy and mean free path behavior of perfect gas and kinetic theory

If the pressure in a closed vessel is reduced by drawing out some gas, the mean-free path of molecules :

  1. is decreased

  2. is increased

  3. remains unchanged

  4. increases or decreases according to the nature of the gas
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The mean-free path of molecule is the distance traveled by a molecule in two consecutive collision. If pressure is reduced and there are less particle then a molecule will travel longer distance before collision, so mean free path is increased.

Multiple choice physics behaviour of perfect gas and kinetic theory of gases mean free path law of equipartition of energy and mean free path behavior of perfect gas and kinetic theory

If the pressure of a gas is increased then its mean free path becomes :

  1. zero

  2. less

  3. more
  4. $\infty$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

As gas pressure increases mean free path of the gas decreases. 
Mean free path is the distance traveled by a gas molecule between two successive collisions.
So, as pressure increases number of collisions increase. Hence, mean free path decreases.