Work doen by air when it expands from 50 liters to 150 liters at a constant pressure of 2 atmospheres is:
Correct answer: A. 2 x 10^4 Joules
- A. 2 x 10^4 Joules
- B. 2 x 10^5 x 100 Joules
- C. 2x100 Joules
- D. 2 x 10^-5 x 100 Joules
Explanation
To calculate the work done by a gas expanding at constant pressure, use the formula W = P∆V. The pressure is given as 2 atmospheres, which needs to be converted to Pascals: 2 atm = 2 x 1.01 x 10⁵ Pa. The change in volume ∆V is the difference between the final and initial volumes, which is 150 liters - 50 liters = 100 liters. Convert the volume from liters to cubic meters: 100 liters = 100 x 1/1000 m³ = 0.1 m³.Therefore, W = 2 x 1.01 x 10⁵ Pa x 0.1 m³ = 2.02 x 10⁴ Joules. However, based on significant figures and rounding, this is approximated to 2 x 10⁴ Joules, which is correctly represented by Option A.Options B, C, and D are incorrect due to errors in unit conversion or misunderstanding the formula.
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