What is a necessary condition for an adiabatic process to occur?
1. ∆T = 0
2. ∆P = 0
3. q = 0
4. w = 0
The enthalpy of formation of all elements in their standard state is-
| 1. | Unity | 2. | Zero |
| 3. | Less than zero | 4. | Different for each element |
for combustion of methane is –x kJ mol–1.
The value of for the same reaction would be:
The enthalpy of combustion of methane, graphite, and dihydrogen at 298 K are, –890.3 kJ mol–1 , –393.5 kJ mol-1, and –285.8 kJ mol–1 respectively. The enthalpy of formation of CH4(g) is:
| 1. | –74.8 kJ mol–1 | 2. | –52.27 kJ mol–1 |
| 3. | +74.8 kJ mol–1 | 4. | +52.26 kJ mol–1 |
For the reaction A + B → C + D + q (kJ/mol), entropy change is positive. The reaction will be :
1. Possible only at high temperature
2. Possible only at low temperature
3. Not possible at any temperature
4. Possible at any temperature
701 J of heat is absorbed by a system and 394 J of work is done by the system. The change in internal energy for the process is:
| 1. | 307 J | 2. | -307 J |
| 3. | 1095 J | 4. | -701 J |
The reaction of cyanamide, with dioxygen, was carried out in a bomb calorimeter, and ∆U was found to be at 298 K:
\(\small{\mathrm{NH}_2 \mathrm{CN}(\mathrm{s})+\frac{3}{2} \mathrm{O}_2(\mathrm{g}) \rightarrow \mathrm{N}_2(\mathrm{g})+\mathrm{CO}_2(\mathrm{g})+\mathrm{H}_2 \mathrm{O}(\mathrm{l})}\)
The enthalpy change for the reaction at 298 K would be:
The amount of heat needed to raise the temperature of 60.0 g of aluminium from 35°C to 55°C would be:
(Molar heat capacity of Al is \(24\) \(J\) \(\text{mol}^{- 1}\) \(K^{- 1}\))
| 1. | \(1 . 07\) \(J\) | 2. | \(1 . 07\) \(kJ\) |
| 3. | \(106 . 7\) \(kJ\) | 4. | \(100 . 7\) \(kJ\) |
The enthalpy of combustion of carbon to CO2 is –393.5 kJ mol-1. The amount of heat released upon formation of 35.2g of CO2 from carbon and dioxygen gas would be:
| 1. | –393.5 kJ mol–1 | 2. | –314.8 kJ mol–1 |
| 3. | +314.8 kJ mol–1 | 4. | –320.5 kJ mol–1 |
The enthalpy of formation of are –110 kJ , – 393 kJ , 81 kJ and 9.7 kJ \(\text{mol}^{- 1}\) respectively. The value of \(\left(\Delta\right)_{r} H\) for the following reaction would be:
\(\mathrm{N_{2} O_{4 \left(g\right)} + 3 CO{\left(g\right)} \rightarrow N_{2} O_{\left(g\right)} + 3CO_{2 \left(g\right)}}\)
| 1. | \(- 777 . 7\) \(kJ\) \(\text{mol}^{- 1}\) | 2. | \(\) \(+ 777 . 7\) \(kJ\) \(\text{mol}^{- 1}\) |
| 3. | \(\) \(+ 824 . 9\) \(kJ\) \(\text{mol}^{- 1}\) | 4. | \(-\) \(345 . 4\) \(kJ\) \(\text{mol}^{- 1}\) |