The ideal gas law is least accurate under conditions of high pressure and low temperature. In those situations, using the van der Waals equation is advisable.
(a) Calculate the pressure exerted by 12.0 g of CO₂ in a 500-mL vessel at 298 K, using the ideal gas equation. Then, recalculate the pressure using the van der Waals equation. Assuming the pressure calculated from van der Waals equation is correct, what is the percent error in the answer when using the ideal gas equation?
(b) Next, cool this sample to −70°C. Then perform the same calculation for the pressure exerted by CO₂ at this new temperature, using both the ideal gas law and the van der Waals equation. Again, what is the percent error when using the ideal gas equation?