- 1(current)
Q. No.Identify the species among the following for which \(\Delta_fH^\circ\) is non-zero:
1. \(S_\text{monoclinic}\)
2. \(C_\text{graphite}\)
3. H2(g)
4. \(O_2(g)\)
1. \(S_\text{monoclinic}\)
2. \(C_\text{graphite}\)
3. H2(g)
4. \(O_2(g)\)
Subtopic: Thermochemistry |
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Consider the following reactions:
| (i) | H+(aq) + OH-(aq) → H2O(l) ΔH = -x1 kJmol-1 |
| (ii) | H2(g) + 1/2O2(g) → H2O(l) ΔH = -x2 kJmol-1 |
| (iii) | CO2(g) + H2(g) → CO (g) + H2O(l) ΔH = -x3 kJmol-1 |
| (iv) | C2H2(g) + 5/2O2(g) → 2CO2 + H2O(l) ΔH = -x4 kJmol-1 |
Enthalpy of formation of H2O(l) is :
1.
2.
3.
4.
Subtopic: Thermochemistry |
76%
Level 2: 60%+
AIPMT - 2007
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The heat of combustion of carbon to CO2 is –393.5 KJ/mol. The heat released upon the formation of 35.2 g of CO2 from carbon and oxygen gas is:
1. –315 KJ
2. +315 KJ
3. –630 KJ
4. +630 KJ
Subtopic: Thermochemistry |
75%
Level 2: 60%+
NEET - 2015
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NEET 2021 - Achiever Batch - Aryan Raj Singh
Given, the following reaction:
Given: ∆ H∘ = 109 kJ/mol
B.E. of (N-N) = 163 kJ/mol
B.E. of (N-H) = 391 kJ/mol
B.E. of (H-H) = 436 kJ/mol
Calculate the bond enthalpy of N = N.
1. 182 kJ/mol
2. 400 kJ/mol
3. 300 kJ/mol
4. 218 kJ/mol
Subtopic: Thermochemistry |
73%
Level 2: 60%+
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NEET 2021 - Achiever Batch - Aryan Raj Singh
| Assertion (A): | All combustion reactions are exothermic. |
| Reason (R): | For an exothermic reaction, enthalpies of products are greater than enthalpies of reactants \({(\Sigma v_p\Delta_fH(P)> \Sigma v_R\Delta_fH(R))}\). |
| 1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
| 3. | (A) is true but (R) is false. |
| 4. | (A) is false but (R) is true. |
Subtopic: Thermochemistry |
63%
Level 2: 60%+
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- 1(current)
Q. No.
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