Question

You want to obtain an answer immediately as to the specific volume of ethane at 700 kPa
and 25°C. List in descending order the techniques you would use with the most preferable
one at the top of the list:
a. Ideal gas law
b. Compressibility charts
c. An equation of state
d. Look up the value on the Web
e. Look up the value in a handbook
Explain your choices.

Answer 1

Descending order of the preferable choices

Equation of state, look up the value in a handbook, look up the value in web, compressibility charts, ideal gas law.

Ideal gas law is least preferable choice because ethane cannot behave as ideal gas, so we need to assume that ethane is behaving as ideal to use that model which may not give accurate values.

Equation of state is preferable because those equations are derived based on empirical values based different operating conditions which would result in accurate values.

The solution that we get from equation of state and the values present in handbook and web would relatively same. So 3 of them would have approximately same preference.

The specific volume of ethane calculated using ideal gas law has been provided below.