Calculate the work done on the system when 1.00 mol of gas held behind a piston expands irreversibly from a volume of 1.00 dm³ to a volume of 10.0 dm³ against an external pressure of 1.00 bar.

1.00 mol of gas in a cylinder is compressed reversibly by increasing the pressure from 1.00 bar to 10.0 bar at a constant temperature of 500 K.  Calculate the work done on the gas by the compression.

The temperature of a copper block of mass 423 g rises by 10.1 °C. Calculate the heat transferred, given that the specific heat capacity of copper is 385 J K^–1 kg^–1.

Raising the temperature of 1.00 dm³ of water from a temperature of 25°C to 100°C at constant pressure requires 312 kJ of heat.  Calculate the molar heat capacity of water at constant pressure.

A calorimeter was calibrated by passing an electrical current through a heater and measuring the rise in temperature that resulted.  When a current of 113 mA from a 24.1 V source was passed through the heater for 254 s, the temperature of the calorimeter rose by 2.61 °C.  Determine the heat capacity of the calorimeter.

A perfect gas expands reversibly at a constant temperature of 298 K so that its volume doubles.  What is the change in the molar internal energy of the gas?

Which of the following statements is always true for a reaction in which there is no non-expansion work?

Calculate the difference between the molar internal energy and the molar enthalpy for a perfect gas at 298.15 K.

For many substances, the variation with temperature of the molar heat capacity at constant pressure of is given by the expression

For copper, a = 22.64 J K^–1 mol^–1, b = 6.28 ´ 10^–3 J K^–2 mol^–1 with the value of c being negligible. Calculate the change in the molar enthalpy of copper when it is heated from 293 to 323 K.

The molar heat capacity at constant volume of argon, Ar, is 12.47 J K mol^–1.  What is the value of the molar heat capacity at constant pressure?

In an experiment to determine its enthalpy of vaporization, liquid tetrachloromethane, CCl₄, was placed in an open boiler that was equipped with a resistive heating coil and brought to the boil at a constant temperature of 350 K and pressure of 1 bar.  The passage of a current of 0.933 A from a 24.0 V supply for 30.0 s was found to result in the vaporization of 3.45 g of tetrachloromethane.  Calculate the standard enthalpy of vaporization of tetrachloromethane at 350 K.

For iodine, I₂, at 114°C, the standard enthalpy of fusion is 16.1 kJ mol^–1 and the standard enthalpy of vaporization is 45.0 kJ mol^–1.  Calculate the standard enthalpy of sublimation at this temperature.

The energy released as heat when liquid propanone, CH₃COCH₃, is burned in a bomb calorimeter at 298.15 K is 1788 kJ mol^–1.  Calculate the enthalpy of combustion of propanone.

Estimate the standard enthalpy change for the process

F₂(g) + 2 e^–(g) ® 2 F^–(g) The F–F bond enthalpy is +155 kJ mol^–1 and the electron gain enthalpy of elemental fluorine, F, is –328 kJ mol^–1.

Estimate the standard enthalpy change for the reaction

N₂(g) + 3 H₂(g) ® 2 NH₃(g) given the following mean bond enthalpies: H–H: +436 kJ mol^–1, N–N: 945 kJ mol^–1 and H–N: 388 kJ mol^–1.

Use the following data to calculate the mean B–Cl bond enthalpy in boron trichloride, BCl₃.

DHʅ(298 K) Enthalpy of atomization of boron

B(s) ® B(g) +590 kJ mol^–1

Enthalpy of atomization of chlorine

Cl₂(g) ® 2 Cl(g) +242 kJ mol^–1

Enthalpy of formation of boron trichloride

B(s) + 3/2 Cl₂(g) ® BCl₃(g) –418 kJ mol^–1

Calculate the standard enthalpy of combustion of phenol, C₆H₅OH, at 298.15 K given that, at this temperature, the standard enthalpy of formation of phenol is –165.0 kJ mol^–1, of liquid water, H₂O is –285.8 kJ mol^–1 and gaseous carbon dioxide, CO₂, is –393.51 kJ mol^–1.

Estimate the standard enthalpy of formation of liquid benzene, C₆H₆, at 298.15 K. At this temperature, the standard enthalpy of atomization of carbon

C(s, graphite) ® C(g) is +717 kJ mol^–1 and the standard enthalpy of vaporization of benzene is 34 kJ mol^–1, whilst the standard bond enthalpy of hydrogen, H₂, is 436 kJ mol^–1.  The mean bond enthalpy of a C₆H₅–H bond is 469 kJ mol^–1 and of an aromatic C–C bond is 452 kJ mol^–1.

Calculate the standard enthalpy change for the hydrogenation reaction

C₂H₄(g) + H₂(g) ® C₂H₆(g) at 298.15 K.  At this temperature, the standard enthalpy of combustion of ethene, C₂H₄, is –1409 kJ mol^–1, of hydrogen, H₂, is –286 kJ mol^–1 and of ethane, C₂H₆ is –1560 kJ mol^–1.

The standard enthalpy of combustion of propane, C₃H₈, is –2.220 ´ 10³ kJ mol^–1 at 400 K.  Use the data below, and Kirchhoff's law, to calculate the standard enthalpy of combustion at 600 K. 

Cʅ_p,m / J K^–1 mol^–1

C₃H₈(g) 73.6

O₂(g) 29.4

H₂O(g) 33.6

CO₂(g) 37.1