Final answer:
The work done by an ideal gas expanding from 1 L to 10 L against an external pressure of 1 bar is -0.9 kJ. The negative sign indicates the work is done by the gas on the surroundings.
Step-by-step explanation:
The student's question pertains to the work done by an ideal gas during expansion against a constant external pressure, a concept from thermodynamics within the field of Chemistry. To find the work done in joules, the formula W = -PextΔV is used, where W is the work done on the gas, Pext is the external pressure, and ΔV is the change in volume.
Given the external pressure is 1 bar, which converts to 100 kPa or 100,000 Pa (since 1 bar = 100 kPa), and the volume change (ΔV) is from 1 L to 10 L, resulting in a ΔV of 9 L, we must first convert liters to cubic meters (since 1 L = 0.001 m3). Thus, ΔV in meters cubed is 0.009 m3. Applying the formula:
W = -PextΔV = - (100,000 Pa) (0.009 m3) = -900 J
Since work done by the gas is in the opposite direction to the force applied by the external pressure, it is negative. This means the gas does 900 J of work on the surroundings. Converting joules to kilojoules (since 1 J = 0.001 kJ), the work done is -0.9 kJ.