Enthalpy of combustion of carbon to carbon dioxide is \(-390.0~\text{kJ mol}^{-1}.\) The amount of heat released when \(35.0~\text{g}\) of \(\mathrm{CO_2}\) is formed from the reaction of carbon and dioxygen gas, is:
1. \(310~\text{kJ}\) 2. \(490~\text{kJ}\)
3. \(245~\text{kJ}\) 4. \(700~\text{kJ}\)
Subtopic:  Enthalpy & Internal energy |
 75%
Level 2: 60%+
NEET - 2024
Hints

Consider the following reaction:
\(\mathrm{A}_2(\mathrm{~g})+3 \mathrm{~B}_2(\mathrm{~g}) \rightarrow 2 \mathrm{AB}_3(\mathrm{~g})\)
If at 300K, the enthalpy change for the above reaction is +15 kJ, then the internal energy change is:
1. 19.98 K J  2. 200 J
3. 1999 J  4. 1.9988 kJ
Subtopic:  Enthalpy & Internal energy |
 77%
Level 2: 60%+
NEET - 2024
Hints

What is the correct relationship between changes in enthalpy and internal energy within the following options?
1. \(\mathrm{\Delta {H}+\Delta {U}=\Delta {nR}} \)
2. \(\mathrm{\Delta {H}=\Delta {U -\Delta n_gRT}}\)
3. \(\mathrm{\Delta {H}=\Delta {U+\Delta n_gRT }}\)
4. \(\mathrm{\Delta {H} -\Delta {U=-\Delta n_gRT}}\)
Subtopic:  Enthalpy & Internal energy |
 83%
Level 1: 80%+
NEET - 2023
Hints

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For the reaction, 2Cl(g)  Cl2(g), the correct option is:
1. \(\Delta_{\mathrm{r}} \mathrm{H}>0\) and \(\Delta_{\mathrm{r}} \mathrm{S}<0 \) 2. \(\Delta_{\mathrm{r}} \mathrm{H}<0\) and \( \Delta_{\mathrm{r}} \mathrm{S}>0 \)
3. \(\Delta_{\mathrm{r}} \mathrm{H}<0 \) and \(\Delta_{\mathrm{r}} \mathrm{S}<0 \) 4. \(\Delta_{\mathrm{r}} \mathrm{H}>0\) and \( \Delta_{\mathrm{r}} \mathrm{S}>0\)
Subtopic:  Enthalpy & Internal energy | Spontaneity & Entropy |
 61%
Level 2: 60%+
NEET - 2020
Hints

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 |
 61%
Level 2: 60%+
AIPMT - 2012
Hints

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%
Level 2: 60%+
AIPMT - 2011
Hints

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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 |
 75%
Level 2: 60%+
AIPMT - 2011
Hints

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 |
 78%
Level 2: 60%+
AIPMT - 2010
Hints

The difference between enthalpy (∆H) and internal energy (∆E) for the given below reaction,
under constant temperature, is:
\(C_{3} H_{8} \left(\right. g \left.\right) + 5 O_{2} \left(\right. g \left.\right) \rightarrow 3 CO_{2} \left(\right. g \left.\right) + 4 H_{2} O \left(\right. l \left.\right)\)

1. + RT 2. – 3RT
3. + 3RT 4. – RT
Subtopic:  Enthalpy & Internal energy |
 85%
Level 1: 80%+
AIPMT - 2003
Hints
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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 |
 77%
Level 2: 60%+
AIPMT - 2001
Hints
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