Problem Set 1


1). A idea gas undergoes isothermal compression, which reduces its volume by 3.08 dm3. The final pressure and volume of the gas are 6.42 bar and 5.38 dm3, respectively. Calculate the original pressure of the gas in (a) bar, (b) atm.

2). At 0.000°C and 1.000 atm, the mass density of the vapor of a hydrocarbon is 1.97 kg m–3. What is the molecular formula of the hydrocarbon under these conditions? What is the hydrocarbon?

3). Calculate the pressure exerted by 1.0 mol C6H6 C2H6 behaving as (a) an ideal gas, (b) a van der Waals gas when it is confined under the following conditions: (i) at 373.15 K in 22.414 dm3, (ii) at 1000 K in 300 cm3.

4). A certain gas obeys the van der Waals equation with a = 0.580 m6 Pa mol–2. Its volume is found to be 3.50 × 10–4 m3 mol–1 at 273 K and 5.0 MPa. From this information calculate the van der Waals constant b. What is the compression factor for this gas at the prevailing temperature and pressure?

5). In an industrial process, nitrogen is heated to 500 K at a constant volume of 1.000 m3. The gas enters the container at 300 K and 100 atm. The mass of the gas is 92.4 kg. Use the van der Waals equation to determine the approximate pressure of the gas at its working temperature of 500 K. For nitrogen, a = 1.352 dm6 atm mol-2, b = 0.0387 dm3 mol-1.

6). Suppose that 10.0 mol C2H6(g) is confined to 4.860 dm3 at 300 K. Predict the pressure exerted by ethane from a) the ideal gas and b) the van der Waals equations of state. Calculate the compression factor based on these calculations. For ethane, a = 5.507 dm6 atm mol-2, b = 0.0651 dm3 mol-1