designed (by Dutch physicist Johannes van der Waals) to predict the relationship between pressure p, volume V and temperature T for gases better than the Ideal Gas Law does:   (p + a n2/V2)(V- nb)= nRT   The van der Waals equation of state. R stands for the gas constant and n for moles of gas. The parameters a and b must be determined for each gas from experimental data. Use the van der Waals equation to answer the questions in the table below.   What are the units of a?   What are the units of b?   For ethane the numerical value of a is 5.507and the numerical value of b is 0.0651. Use the van der Waals equation to calculate the pressure of a sample of ethane at 55.0°C with a molar volume of 0.781/Lmol. Round your answer to 3 significant digits. atm Use the Ideal Gas Law to calculate the pressure of the same sample under the same conditions. Round

Sometimes in lab we collect the gas formed by a chemical reaction over water (see sketch at right). This makes it easy to isolate and measure the amount of gas produced. 2 Suppose the CO₂ gas evolved by a certain chemical reaction taking place at 40.0 °C is collected over water, using an apparatus something like that in the sketch, and the final volume of gas in the collection tube is measured to be 51.0 mL. g x10 X 歐 Sketch of a gas-collection apparatus S collected gas Calculate the mass of CO₂ that is in the collection tube. Round your answer to 2 significant digits. You can make any normal and reasonable assumption about 2 the reaction conditions and the nature of the gases. water chemical reaction

Answer part a and b

I only need help with part b