# Equation of State - MCQs with Answers

Q1. In which condition can real gas obey closely the ideal gas equation?

a. pressure is very small and temperature is very high
b. pressure is very high and temperature is very low
c. both pressure and temperature are very high
d. both pressure and temperature are very low

ANSWER: a. pressure is very small and temperature is very high

Q2. The equation pv=RT is used for ideal gases. The right equation for real gases is van der Waals equation. What is the correct formula for the van der Waals equation?
Where
(a/v2)= force of cohesion
b= coefficient related to volume of molecules

a. (p+(a/v2)) (v + b) = RT
b. (p – (a/v2)) (v – b) = RT
c. (p + (a/v2)) (v – b) = RT
d. (p – (a/v2)) (v + b) = RT

ANSWER: c. (p + (a/v2)) (v – b) = RT

Q3. In high pressure condition, the real gases conform more closely with

a. van der Waals equation
b. ideal gas equation
c. both a. and b.
d. none of the above

ANSWER: a. van der Waals equation

Q4. What is reduced property of a substance?

a. critical property of a substance minus existing property of the same substance
b. existing property of a substance minus critical property of the same substance
c. ratio of critical property to existing property of the same substance
d. ratio of existing property to critical property of the same substance