Plz someone answer my question..

Z = 1 - a/VRT

Explanation:

Note :

Compressibility Factor, Z = PV / RT

Vander waal forces at Lower pressure is represented by the expression :

V[P + a/V²] = RT

Aim is to move PV /RT =Z to one side of the equation.

Using change of subject :

opening the bracket :

PV + aV / V² = RT

PV + a/V = RT

Divide through by RT

PV/RT + a/VRT = RT/RT

PV/RT + a/VRT = 1

Recall:

PV /RT = Z

equation becomes :

Z + a/VRT = 1

Subtract a/VRT from both sides

Z + a/VRT - a/VRT = 1 - a/VRT

Z = 1 - a/VRT

the ideal gas law equation is as follows

pv = nrt

where p - pressure

v - volume

n - number of moles

r - universal gas constant

t - temperature

so if the pressure, volume and temperature are already known

we are left with n and r

since r is the universal gas constant that has a known fixed value then r too is known

so we are left with 'n'

once we know temperature volume and pressure

we can find the number of moles of gas present using the ideal gas law equation

this is not my own answer, this is an answer for the same question by the user blahblahmali. i do not claim ownership of this account.

po-215 i got it right on the quiz