What is the correct relationship between changes in enthalpy and internal energy within the following options?

1. \(\Delta \mathrm{H}+\Delta \mathrm{U}=\Delta \mathrm{nR} \)
2. \(\Delta \mathrm{H}=\Delta \mathrm{U}-\Delta n_gRT\)
3. \(\Delta \mathrm{H}=\Delta \mathrm{U}+\Delta n_gRT \)
4. \(\Delta \mathrm{H} -\Delta \mathrm{U}=-\Delta n_gRT\)
Subtopic:  Enthalpy & Internal energy |
 81%
From NCERT
NEET - 2023
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For the reaction, 2Cl(g)  Cl2(g), the correct option is:

1. rH>0 and rS<0

2. rH<0 and rS>0

3. rH<0 and rS<0

4. rH>0 and rS>0

Subtopic:  Enthalpy & Internal energy | Spontaneity & Entropy |
 60%
From NCERT
NEET - 2020
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The standard enthalpy of vaporization vapHo for water at 100 oC is 40.66 kJ mol-1.
The internal energy of vaporization of water at 100 oC (in kJ mol-1) is: 
(Assume water vapour behaves like an ideal gas.)

1. +37.56

2. -43.76

3. +43.76

4. +40.66

Subtopic:  Enthalpy & Internal energy |
 59%
From NCERT
AIPMT - 2012
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Given the following reaction:
\(4H(g)\)→  \(2 H_{2}\)\((g)\)
The enthalpy change for the reaction is -869.6 kJ. The dissociation energy of the H-H bond is:
1. -869.6 kJ
2. +434.8kJ
3. +217.4kJ
4. -434.8 kJ

Subtopic:  Enthalpy & Internal energy |
 68%
From NCERT
AIPMT - 2011
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Consider the following processes:

                                       ∆H (kJ/mol)
½ A → B                            + 150
3B → 2C + D                      –125
E + A → 2D                        +350

For B + D → E + 2C, ∆H will be-

1. 325 kJ/mol 

2. 525 kJ/mol

3. –175 kJ.mol 

4. –325 kJ/mol

Subtopic:  Enthalpy & Internal energy |
 72%
From NCERT
AIPMT - 2011
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The following two reactions are knownFe2O3(s)+3CO(g)2Fe(s)+3CO2(g);
H=-26.88 kJ
FeO(s)+CO(g)Fe(s)+CO2(g);
H=-16.5 kJ

The value of H for the following reaction

Fe2O3(s)+CO(g)2FeO(s)+CO2(g) is:

1. -43.3 kJ

2. -10.3 kJ

3. +6.2 kJ

4. +10.3 kJ

Subtopic:  Enthalpy & Internal energy |
 76%
From NCERT
AIPMT - 2010
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For the reaction:

\(C_{3} H_{8} \left(\right. g \left.\right) + 5 O_{2} \left(\right. g \left.\right) \rightarrow 3 CO_{2} \left(\right. g \left.\right) + 4 H_{2} O \left(\right. l \left.\right)\) at constant temperature, ∆H – ∆E is:

1. + RT 2. – 3RT
3. + 3RT 4. – RT
Subtopic:  Enthalpy & Internal energy |
 83%
From NCERT
AIPMT - 2003
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NEET 2023 - Target Batch - Aryan Raj Singh
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For the given reaction 

2H2O2(l)  2H2O(l) + O2(g), the heat of formations of H2O2(l)  and H2O (l) are -188 kJ/mol & -286 KJ/mol respectively. The change in the enthalpy of the reaction will be:

1.  – 196 kJ/mol

2.  + 196 kJ/mol

3.  + 948 kJ/mol

4.  – 948 kJ/mol

Subtopic:  Enthalpy & Internal energy |
 74%
From NCERT
AIPMT - 2001
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Enthalpy  of CH4 + 12O2  CH3OH is negative. If the enthalpy of combustion of CH4 and CH3OH are x and y respectively, then which relation is correct:

1. x > y 2. x < y
3. x = y 4. x ≥ y
Subtopic:  Enthalpy & Internal energy |
 62%
From NCERT
AIPMT - 2001
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NEET 2023 - Target Batch - Aryan Raj Singh
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For the reaction
C2H5OH(l) + 3O2(g) →2CO2(g) + 3H2O(l) which one is true:

1. ∆H = ∆E – RT 2. ∆H = ∆E + RT
3. ∆H = ∆E + 2RT 4. ∆H = ∆E – 2RT
Subtopic:  Enthalpy & Internal energy |
 84%
From NCERT
AIPMT - 2000
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NEET 2023 - Target Batch - Aryan Raj Singh
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