- #1

MechE2015

- 19

- 0

## Homework Statement

Find the volume of 2 kg of ethylene at 270 K, 2500 kPa using Z

## Homework Equations

Method to Solve for Z, Using Tr and Pr

PV = ZnRT

## The Attempt at a Solution

Tr = 0.9561

Pr = 0.496

Z found to be approx. 0.75

R given on a table at 0.2964 kJ/kg K

From here, I should have all information needed, I was just confused on units at this point.

V = ZnRT/P

V = (0.75)*(n)*(0.2964 kJ/kg K)*(270 K) / (2500 kPa)

At this point, my main questions are (probably very simple):

What is n, and why? My best guess: (2000 g)/(28 g/mol) = 71.43 mol

What are units for P? My best guess: atm, -> 2500 kPa*24.67 atm/kPa = 61675 atm

Using these numbers, I get Volume to be way too low, corrections needed somewhere. Help appreciated.