One mole of a non-ideal gas undergoes a change of state (2.0 atm, 3.0 L, 95 K)(4.0 atm, 5.0 L, 245 K) with a change in internal energy, U = 30.0 L atm. The change in enthalpy (H) of the process in L atm is:

1. 40.0

2. 42.3

3. 44.0

4. not defined, because pressure is not constant

Subtopic:  First Law of Thermodynamics |
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

According to the law, a perfect crystal's entropy is 0 at absolute zero, which is:

1. The first law               

2. Second law

3. Third law             

4. None of the above

Subtopic:  Spontaneity & Entropy |
 60%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

At constant pressure and temperature, the direction of any chemical reaction is one where the...... decrease.

1. Entropy               

2. Enthalpy

3. Gibbs energy       

4. None of the above

Subtopic:  Spontaneity & Entropy |
 55%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

The work done by a mass less piston in causing an expansion V (at constant temperature), when the opposing pressure, P is variable, is given by:

1. W= -PV               

2. W=0

3. W= -PV                     

4. none of these

Subtopic:  2nd & 3rd Law of Thermodynamics |
 64%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

Entropy decreases during:

1. crystallization of sucrose from solution

2. rusting of iron

3. melting of ice

4. vaporization of camphor

Subtopic:  Spontaneity & Entropy |
 72%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

Entropy change of vaporization at constant pressure is given by:

1. S(p)= HpT

2. S(v)=UvT

3. S(v)= HvP

4. None of the above

Subtopic:  Spontaneity & Entropy |
 75%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

What is the entropy change for the reaction given below, 

2H2 (g) + O2 (g) 2H2O(l)

at temperature 300 K? Standard entropies of H2 (g), O2(g) and H2O(l) are 126.6, 201.20 and 68.0 JK-1mol-1 respectively.

1. -318.4 JK-1mol-1                           .

2. 318.4 JK-1mol-1 

3. 31.84 JK-1mol-1                             

4. none of these

Subtopic:  Spontaneity & Entropy |
 72%
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints

If S° for H2, Cl2 and HCl are 0.13, 0.22 and 0.19 kJ K-1mol-1 respectively. The total change in standard entropy for the reaction, H2 + Cl2 2HCl is:

1. 30 J K-1mol-1                         

2. 40 J K-1mol-1

3. 60 J K-1mol-1                         

4. 20 J K-1mol-1

Subtopic:  Spontaneity & Entropy |
 80%
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints

The direct conversion of A to B is difficult and thus it is converted by path ACDB. Given

SAC=50 e.u; SCD=30 e.u; SBD=20 e.u.

(Where e.u. is the entropy unit)
then SAB would be:

1. +60 e.u                                       

2. +100 e.u

3. -60 e.u                                       

4. -100 e.u

Subtopic:  Hess's Law |
 60%
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints

In a flask, colourless N2O4(g) is in equilibrium with brown coloured NO2(g). At equilibrium when the flask is heated to 100°C, the brown colour deepens and on cooling it becomes less coloured. Which statement is incorrect about this observation?

1. The H for the reaction N2O4(g) 2NO2(g) is +ve

2. Paramagnetism increases on heating

3. The H-U at 100°C is equal to 200 cal

4. Dimerisation is reduced on heating

Subtopic:  First Law of Thermodynamics |
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh