Thermodynamics

16 g of oxygen gas expands isothermally and reversibly at 300 K from 10 dm³ to 100 dm³. The work done is (in J)

• zero

• - 2875 J

• + 2875 J

• infinite

$$\begin{gathered} \mathrm{If} \mathrm{C}\left(\mathrm{s}\right) + {\mathrm{O}}_2\left(\mathrm{g}\right) \to \mathrm{CO}\left(\mathrm{g}\right); ∆\mathrm{H} = \mathrm{r} \\ \mathrm{and} \mathrm{CO}\left(\mathrm{g}\right) + \frac{1}{2}{\mathrm{O}}_2\left(\mathrm{g}\right) \to {\mathrm{CO}}_2\left(\mathrm{g}\right); ∆\mathrm{H} =\mathrm{s} \mathrm{then}, \mathrm{the} \mathrm{heat} \mathrm{of} \mathrm{formation} \mathrm{of} \mathrm{CO} \mathrm{is} \end{gathered}$$

• r+s

• r-s

• s-r

• rs

Heat of combustion of methane is -800 kJ. What is the heat of combustion for 4 × 10^-4 kg of methane?

• -800 kJ

• -3.2 × 10⁴ kJ

• -20 kJ

• -1600 kJ

Kirchhoff's equation is

• $\log \frac{{\mathrm{k}}_2}{{\mathrm{k}}_1} = \frac{{\mathrm{E}}_{\mathrm{a}}}{2.303 \mathrm{R}} \left[\frac{1}{{\mathrm{T}}_1} - \frac{1}{{\mathrm{T}}_2}\right]$

• $\log \frac{{\mathrm{p}}_2}{{\mathrm{p}}_1} = \frac{∆{\mathrm{H}}_{\mathrm{v}}}{2.303 \mathrm{R}} \left[\frac{{\mathrm{T}}_2 - {\mathrm{T}}_1}{{\mathrm{T}}_1 \times {\mathrm{T}}_2}\right]$

• $∆{\mathrm{C}}_{\mathrm{p}} = \frac{∆{\mathrm{H}}_2 - ∆{\mathrm{H}}_1}{{\mathrm{T}}_2 - {\mathrm{T}}_1}$

• $\text{log }\frac{{\mathrm{k}}_2}{{\mathrm{k}}_1} = \frac{∆\mathrm{H}}{2.303 \mathrm{R}} \left[\frac{1}{{\mathrm{T}}_1} - \frac{1}{{\mathrm{T}}_2}\right]$

The heat of combustion of carbon is - 393.5 kJ/mol. The heat released upon the formation of 35.2 g of CO₂ from carbon and oxygen gas is

• + 315 kJ

• - 31.5 kJ

• - 315 kJ

• + 31.5 kJ

Assuming enthalpy of combustion of hydrogen at 273 K is -286 kJ and enthalpy of fusion of ice at the same temperature to be +6.0 kJ, calculate enthalpy change during formation of 100 g of ice.

• +1622 kJ

• - 1622 kJ

• +292 kJ

• - 292 kJ

For which among the following reactions, change in entropy is less than zero?

• Sublimation of iodine

• Dissociation of hydrogen

• Formation of water

• Thermal decomposition of calcium carbonate

Which among the following is a feature of adiabatic expansion?

• $∆$V < 0

• $∆$U < 0

• $∆$U > 0

• $∆$T = 0

What is the amount of work done when two moles of ideal gas is compressed from a volume of 1m³ to 10 dm³ at 300 K against a pressure of 100 kPa?

• 99 kJ

• -99kJ

• 114.9 kJ

• -114.9 kJ

The work done during combustion of 9 × 10^-2 kg of ethane, C₂H₆ (g) at 300 K is (Given R = 8.314 J deg^-1 mol^-1, atomic mass C = 12, H= 1).

• 6.236 kJ

• -6.236 kJ

• 18.71 kJ

• -18.71 kJ