The reaction of cyanamide, NH₂CN_(s) with oxygen was run in a bomb calorimeter and $∆$U was found to be –742.24 kJ mol^–1. The magnitude of ${\mathrm{\Delta H}}_{298}$(KJ) for the given-below reaction is:

NH₂CN_(s) + \(\frac{3}{2}\)O_2(g) → N_2(g) + O_2(g) + H₂O_(l) 

[Assume ideal gases and \(\mathrm{R}=8.314 \mathrm{~J} \mathrm{~mol}^{-1} \mathrm{~K}^{-1}\)]$$

The internal energy change (in kJ) when 90g of water undergoes complete evaporation at 100ºC is -

(Given : $∆$H_vap for water at 373 K = 41 kJ/mol, R = 8.314 JK^–1mol^–1)

1. 154.5

2. 168.5

3. 176.5

4. 189.5

For one mole of an ideal gas, which of these statements must be true?
(I) U and H each depend only on temperature.
(II) Compressibility factor z is not equal to 1.
(III) C_{P, m} – C_{V, m} = R
(IV) dU = C_VdT for any process.
1. (I), (III) and (IV)
2. (II), (III) and (IV)
3. (III) and (IV)
4. (I) and (III)

If, for a dimerization reaction, 2A_(g) → A_2(g)  at   298 K , ∆U^Θ = -20 kJ mol^-1   ∆S^Θ   = - 30 J K^-1mol^-1 , then ∆G^Θ  will be:

1. -10. 4 kJ

2. 18.9 kJ

3. -13.5 kJ

4. 17. 4 kJ

What is the change in internal energy for 5 moles of an ideal gas when it undergoes reversible compression from 100 K to 200 K? 
(Given C_V = 28 J K^–1 mol^–1)​​​​​​

What is the difference between \(\Delta H\) and \(\Delta U\) \((\Delta H - \Delta U)\) when the combustion of one mole of heptane(l) is carried out at a temperature T?

Enthalpy of sublimation of iodine is 24 cal g^–1 at 200 °C. If specific heat of I₂(s) and l₂ (vap) are 0.055 and 0.031 cal g^–1K^–1 respectively, then enthalpy of sublimation of iodine at 250°C in cal g^–1 is :
1.  2.85
2.  22.8
3.  11.4
4.  5.7

The value of enthalpy change ($∆$H) for the reaction

${\mathrm{C}}_2{\mathrm{H}}_5{\mathrm{OH}}_{\left(1\right)}+3{\mathrm{O}}_{2\left(\mathrm{g}\right)}\to 2{\mathrm{CO}}_{2\left(\mathrm{g}\right)}+3{\mathrm{H}}_2{\mathrm{O}}_{\left(\mathrm{l}\right)}$ at $27°C$ is -1366.5 kJ mol^-1.

Assuming that water vapor is an ideal gas, the internal energy change (∆U) when 1 mol of water is vaporized at 1 bar pressure and 100°C, will be:

(Given: Molar enthalpy of vaporization of water at 1 bar and 373 K = 41 kJ mol^–1 and R = 8.3 J mol^–1 K^–1) 

1. 4.100 kJ mol^–1

2. 3.7904 kJ mol^–1

3. 37.904 kJ mol^–1

4. 41.00 kJ mol^–1