Question

A gas is compressed from an initial volume of 5.55 L to a final volume of 1.22 L

            by an external pressure of 0.975 atm. Which of the following statements is/are true?

(1 L·atm = 101.3 J). Choose the single best answer

A.   Work = 428 J

B.   The gas does work on the surroundings.

C.   Work = 4.22 J

D. The gas loses energy during the compression.

E.   Two of the above are true.

Answer 1

Ans.

Initial volume = 5.55L

Final volume = 1.22L

Change in volume is

External pressure, P = 0.975 atm

1 L.atm = 101.3J

1 atm = 101.3 J/L

Therefore,

Calculate work using the formula

Therefore, work = 428J

Option (A) is correct.

The positive sign of work indicates that work is done on the gas.

So, option (B) is wrong.

Option (C) is also wrong since work is not equal to 4.22J

Option (D) is also wrong since during compression, the internal energy of a gas increases.

The correct answer is option (A).