Chapter 5, Problem 5.81P

The thermal decomposition of ethylene occurs during the compound’s transit in pipelines and during the formation of polyethylene. The decomposition reaction is ${\text{CH}}_{\text{2}}={\text{CH}}_{\text{2}}\text{(g) }\to {\text{ CH}}_{\text{4}}(g)+\text{C}(graphit\text{e})$ If the decomposition begins at 10°C and 50.0 atm with a gas density of 0.215 g/mL and the temperature increases by 950 K,

(a) What is the final pressure of the confined gas (ignore the volume of graphite and use the vander Waals equation)?

(b) How does the PV/RT value of ${\text{CH}}_{\text{4}}$ compare to that in Figure 5.21? Explain.