Q. No.Which of the following statements is/are correct?
1. a and b
2. b, c and d
3. b and c
4. None of the above
| (a) | Heat is a way of transferring energy. |
| (b) | Heat is not a property of the system, whereas temperature is a property of the system. |
| (c) | Reactions that are accompanied by the evolution of heat are called endothermic reactions. |
| (d) | Those reactions in which heat is absorbed are known as exothermic reactions. |
1. a and b
2. b, c and d
3. b and c
4. None of the above
Subtopic: First Law of Thermodynamics | Classification of System, Extensive & Intensive Properties | Thermochemistry |
83%
Level 1: 80%+
Please attempt this question first.
Hints
Please attempt this question first.
Match Column I (Reactions) with Column II (Enthalpy) and mark the appropriate choice:
1. (A) →(iv), (B)→(iii), (C) →(i), (D)→ (ii)
2. (A) →(ii), (B)→(i), (C) →(iv), (D)→ (iii)
3. (A) →(i), (B)→(ii), (C) →(iii), (D)→ (iv)
4. (A) →(iii), (B)→(iv), (C) →(ii), (D)→ (i)
| Column I (Reactions) | Column II (Enthalpy) | ||
| (A) | \(\small{CH_{4(g)} + 2O_{2(g)} \rightarrow CO_{2(g)} + 2H_2O}\) | (i) | \(\Delta _{sol}H^o\) |
| (B) | \( H_{2(g)} \rightarrow 2H_{(g)}\) | (ii) | \(\Delta _{lattice}H^o\) |
| (C) | \(NaCl_{(s)} \rightarrow Na^+_{(g)} + Cl^-_{(g)} \) | (iii) | \(\Delta _{c}H^o\) |
| (D) | \(NaCl_{(s)} \rightarrow Na^+_{(aq)} + Cl^-_{(aq)} \) | (iv) | \(\Delta _{bond}H^o\) |
1. (A) →(iv), (B)→(iii), (C) →(i), (D)→ (ii)
2. (A) →(ii), (B)→(i), (C) →(iv), (D)→ (iii)
3. (A) →(i), (B)→(ii), (C) →(iii), (D)→ (iv)
4. (A) →(iii), (B)→(iv), (C) →(ii), (D)→ (i)
Subtopic: Thermochemistry |
89%
Level 1: 80%+
Please attempt this question first.
Hints
Please attempt this question first.
The enthalpy change for the reaction is called
1. Enthalpy of formation
2. Enthalpy of vaporisation
3. Enthalpy of sublimation
4. Enthalpy of combustion
Subtopic: Thermochemistry |
89%
Level 1: 80%+
Please attempt this question first.
Hints
Please attempt this question first.
Consider a reaction:
\(A_2 + B_2 \rightarrow 2AB\\ (g)~~~~(g)~~~~~~~~(g) \)
If \(\Delta H^o_f \) of \(A_2 , AB \) and \(B_2\) are in the ratio \(1: {1 \over 2}: 1\) and \(\Delta H \) of the reaction is -200 kJ/mol. The value of \(\Delta H^o_f~ (A_2)\)(kJ mol-1) is:
1. 250
2. 200
3. 300
4. 240
\(A_2 + B_2 \rightarrow 2AB\\ (g)~~~~(g)~~~~~~~~(g) \)
If \(\Delta H^o_f \) of \(A_2 , AB \) and \(B_2\) are in the ratio \(1: {1 \over 2}: 1\) and \(\Delta H \) of the reaction is -200 kJ/mol. The value of \(\Delta H^o_f~ (A_2)\)(kJ mol-1) is:
1. 250
2. 200
3. 300
4. 240
Subtopic: Thermochemistry |
89%
Level 1: 80%+
Please attempt this question first.
Hints
Please attempt this question first.
Consider the following reaction:
\(\mathrm{2H_2(g) + O_2(g) \rightarrow 2H_2O(g); ~\Delta_rH^\circ = -483.64~ kJ }\)
What is the enthalpy change (in KJ) for the decomposition of one mole of water?
\(\mathrm{2H_2(g) + O_2(g) \rightarrow 2H_2O(g); ~\Delta_rH^\circ = -483.64~ kJ }\)
What is the enthalpy change (in KJ) for the decomposition of one mole of water?
| 1. | 120.9 | 2. | 241.82 |
| 3. | 18 | 4. | 100 |
Subtopic: Thermochemistry |
89%
Level 1: 80%+
NEET - 2023
To unlock all the explanations of this course, you need to be enrolled.
Hints
To unlock all the explanations of this course, you need to be enrolled.
Given the following reaction:
\(\mathrm{C}_2 \mathrm{H}_4(g)+6 \mathrm{~F}_2(g) \rightarrow 2 \mathrm{CF}_4(g)+4 \mathrm{HF}(g)\)
Which species has a standard enthalpy of formation \((\Delta H^{\circ})\) equal to 0?
1. \(\mathrm{C}_2 \mathrm{H}_4\)
2. \(\mathrm{F}_2\)
3. \(\mathrm{CF}_4\)
4. \(\mathrm{HF}\)
\(\mathrm{C}_2 \mathrm{H}_4(g)+6 \mathrm{~F}_2(g) \rightarrow 2 \mathrm{CF}_4(g)+4 \mathrm{HF}(g)\)
Which species has a standard enthalpy of formation \((\Delta H^{\circ})\) equal to 0?
1. \(\mathrm{C}_2 \mathrm{H}_4\)
2. \(\mathrm{F}_2\)
3. \(\mathrm{CF}_4\)
4. \(\mathrm{HF}\)
Subtopic: Thermochemistry |
86%
Level 1: 80%+
Please attempt this question first.
Hints
Please attempt this question first.
The standard heat of combustion of carbon (graphite) to CO₂ is –393.5 kJ mol⁻¹. Calculate the heat released when 15.84 g of CO₂ is formed from carbon (graphite) and oxygen gas:
1. 212.49 kJ2. 141.66 kJ
3. 21.25 kJ
4. 42.5 kJ
Subtopic: Thermochemistry |
86%
Level 1: 80%+
Please attempt this question first.
Hints
Please attempt this question first.
The enthalpy of vaporisation of a liquid is 30 kJ mol–1 and entropy of vaporisation is 75 J mol–1 k–1. What is the boiling point of the liquid at 1 atm?
| 1. | 50 K | 2. | 400 K |
| 3. | 450 K | 4. | 600 K |
Subtopic: Thermochemistry |
87%
Level 1: 80%+
Please attempt this question first.
Hints
Please attempt this question first.
The standard enthalpies of formation of diamond and fullerene are 1.90 kJ mol⁻¹ and 38.1 kJ mol⁻¹, respectively. Calculate the enthalpy change for the conversion of diamond to fullerene:
2. 36.2 kJ mol-1
3. 40 kJ mol-1
4. 57.1 kJ mol-1
Subtopic: Thermochemistry |
87%
Level 1: 80%+
Please attempt this question first.
Hints
Please attempt this question first.
What is the enthalpy change (ΔH) for the reaction represented by the equation, \(\mathrm{OF_2 + H_2O \rightarrow O_2+2HF?}\)
[Given the bond energies of \(\mathrm{O-F, O-H, H-F}\) \(\mathrm {and~O=O}\) as 44, 111, 135, and 119 kcal mol–1, respectively]
[Given the bond energies of \(\mathrm{O-F, O-H, H-F}\) \(\mathrm {and~O=O}\) as 44, 111, 135, and 119 kcal mol–1, respectively]
| 1. | –222 kcal | 2. | –88 kcal |
| 3. | –111 kcal | 4. | –79 kcal |
Subtopic: Thermochemistry |
86%
Level 1: 80%+
Please attempt this question first.
Hints
Please attempt this question first.
© 2026 GoodEd Technologies Pvt. Ltd.