# Properties of Gases and Gas Mixtures - Mechanical Engineering (MCQ) questions and answers

1)   The perfect example of an ideal gas is

a. air
b. hydrogen
c. water vapour
d. none of the above
 Answer  Explanation ANSWER: none of the above Explanation: No explanation is available for this question!

2)   What is an ideal gas?

a. which obeys the law pv = RT
b. which obeys the law p = vR / T
c. which obeys the law pv = R / T
d. none of the above
 Answer  Explanation ANSWER: which obeys the law pv = RT Explanation: No explanation is available for this question!

3)   According to the Avogadro's law, what is the relation between volume of 1 kg mol of oxygen and volume of 1 kg mol of nitrogen, at normal pressure and temperature? (Mass of 1 kg mol of oxygen is 32 kg and mass of 1 kg mol of nitrogen is 28 kg)

a. volume of 1 kg mol of oxygen is greater than that of nitrogen
b. volume of 1 kg mol of oxygen is less than that of nitrogen
c. volume of 1 kg mol of oxygen is same as that of nitrogen
d. none of the above
 Answer  Explanation ANSWER: volume of 1 kg mol of oxygen is same as that of nitrogen Explanation: No explanation is available for this question!

4)   The sum of partial volumes of all gases in a mixture is equal to

a. less than the total volume of the mixture
b. the total volume of the mixture
c. more than the total volume of the mixture
d. cannot predict
 Answer  Explanation ANSWER: the total volume of the mixture Explanation: No explanation is available for this question!

5)   What is the partial volume of a gas in a mixture?

a. volume occupied by a single gas alone of a mixture at the same temperature and pressure of the mixture
b. total volume of the mixture at a certain pressure and temperature divided number of gases mixed in the mixture
c. both a. and b.
d. none of the above
 Answer  Explanation ANSWER: volume occupied by a single gas alone of a mixture at the same temperature and pressure of the mixture Explanation: No explanation is available for this question!

6)   Dalton's law of partial pressure states that

a. the total pressure of a mixture of ideal gases is equal to the sum of the partial pressures of individual gases divided by number of gases mixed

b. the total pressure of a mixture of ideal gases is equal to the partial pressure of any individual gas in the mixture

c. the total pressure of a mixture of ideal gases is equal to the sum of the partial pressures of individual gases

d. none of the above
 Answer  Explanation ANSWER: the total pressure of a mixture of ideal gases is equal to the sum of the partial pressures of individual gases Explanation: No explanation is available for this question!

7)   A mixture of ideal gases of volume V at temperature T, contains n1 moles of gas A, n2 moles of gas B and n3 moles of gas C. What is a correct formula for partial pressure (pB) of gas B?

a. (pB) = ((1/3)(n1+n2+n3) RT) / V

b. (pB) = ((n1 + n3) RT) / V
c. (pB) = (n2 RT) / V
d. (pB) = (n2(n1 + n3) RT) / V
 Answer  Explanation ANSWER: (pB) = (n2 RT) / V Explanation: No explanation is available for this question!

8)   In a mixture of ideal gases of volume V and temperature T, what is the pressure exerted by each individual gas if it occupies the total volume V alone at temperature T called?

a. individual pressure
b. divided pressure
c. partial pressure
d. total pressure
 Answer  Explanation ANSWER: partial pressure Explanation: No explanation is available for this question!

9)   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
 Answer  Explanation ANSWER: ratio of existing property to critical property of the same substance Explanation: No explanation is available for this question!

10)   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  Explanation ANSWER: van der Waals equation Explanation: No explanation is available for this question!

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