Answer:
(a) 0 J
(b) -9.5 J
(c) -18 J
Explanation:
A gas expands in volume from 26.7 to 89.3 mL at constant temperature. The change in volume is:
ΔV = 89.3 mL - 26.7 mL = 62.6 mL = 0.0626 L
The work done (w) can be calculated using the following expression.
w = - P × ΔV
where,
P is the pressure
(a) against a vacuum (P = 0)
w = - P × ΔV = - 0 atm × 0.0626 L = 0 atm . L = 0 J
(b) against a constant pressure of 1.5 atm
w = - P × ΔV = - 1.5 atm × 0.0626 L × (101.3 J/1 atm.L) = -9.5 J
(c) against a constant pressure of 2.8 atm
w = - P × ΔV = - 2.8 atm × 0.0626 L × (101.3 J/1 atm.L) = -18 J
