Question

The Vander Waal's equation of state reduces itself to the ideal gas equation at?

• A. high pressure and low temperature
• B. low pressure and low temperature
• C. low pressure and high temperature
• D. high pressure and high temperature

Answer 1

The correct option is C low pressure and high temperature

Van der Waals equation is given by,

$(P+\frac{a}{V^2})(V-b)=RT$

At low pressure, volume is very large. Hence correction factor $b$ can be neglected. At low pressure & high temperature factors $a$ & $b$ are very small & can be neglected. Thus the real gases approach ideal behaviour.