Calculate thange in enthalpy for a given reaction,

2H2O2(l) 2H2O(l) + O2(g)

(Given the heat of formation of H2O2(l) and H2O(l) are -188 and -286 kJ/mol
respectively)       

1. -196 kJ/mol             

2. + 196 kJ/mol

3. +948 kJ/mol             

4. -948 kJ/mol

Subtopic:  Enthalpy & Internal energy |
 68%
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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 |
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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%
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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%
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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 |
 65%
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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
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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%
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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%
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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%
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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%
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