Q. No.The pair of isochoric among the transformation of state is:
1. K to L and L to M
2. L to M and N to K
3. L to M and M to N
4. M to N and N to K
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 and 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
Thermodynamics is not concerned about which of the following?
| 1. | Energy changes involved in a chemical reaction. |
| 2. | The extent to which a chemical reaction proceeds. |
| 3. | The rate at which a reaction proceeds. |
| 4. | The feasibility of a chemical reaction. |
Reversible expansion of an ideal gas under isothermal and adiabatic conditions are shown in the figure:
ABIsothermal expansion
ACAdiabatic expansion
Which of the following options is not correct?
| 1. | \(\Delta S_{\text {isothermal }}>\Delta S_{\text {adiabatic }} \) | 2. | \(T_A=T_B \) |
| 3. | \(W_{\text {isothermal }}>W_{\text {adiabatic }} \) | 4. | \(T_C>T_A\) |
What is the amount of work done by an ideal gas, if the gas expands isothermally from \(10^{-3}~m^3\) to \(10^{-2}~m^3\) at \(300~K\)against a constant pressure of \(10^{5}~Nm^{-2}\)?
| 1. | \(+270 ~kJ\) | 2. | \(–900 ~J\) |
| 3. | \(+900 ~kJ\) | 4. | \(–900~ kJ\) |
If for a certain reaction is 30 kJ mol–1 at 450 K, the value of (in JK–1 mol–1) for which the same reaction will be spontaneous at the same temperature is:
| 1. | 70 | 2. | –33 |
| 3. | 33 | 4. | –70 |
Identify the correct statement regarding entropy:
| 1. | At absolute zero of temperature, the entropy of all crystalline substances is taken to be zero. |
| 2. | At absolute zero of temperature, the entropy of a perfectly crystalline substance is positive. |
| 3. | At absolute zero of temperature, the entropy of a perfectly crystalline substance is taken to be zero. |
| 4. | At 0 °C , the entropy of a perfectly crystalline substance is taken to be zero. |
When 1 mol gas is heated at constant volume, the temperature is raised from 298 to 308 K. Heat supplied to the gas is 500 J. The correct statement among the following is:
1. q = w = 500 J, ∆U = 0
2. q = ∆U = 500 J, w = 0
3. q =0, w = 500 J, ∆U = 0
4. ∆U = 0, q = w = – 500 J
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.
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 |
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