Question

a chemical reaction is performed in a flask that is sealed with a piston. the initial volume of the system is 5.00 l and after the reaction is complete the final volume is 4.00 l. the outside pressure remains constant at 1 atm. given that 1 l - atm = 101.325 j, calculate the work of the system (the reaction).+101 j+20.0 j-101 j-20.0 j-1.00 j+1.00 j

Explanation:

Step1: Recall the formula for work at constant pressure

The formula for work \(w\) at constant pressure \(P\) is \(w=-P\Delta V\), where \(\Delta V = V_{final}-V_{initial}\).

Step2: Calculate the change in volume \(\Delta V\)

Given \(V_{initial}=5.00\space L\) and \(V_{final} = 4.00\space L\), then \(\Delta V=4.00 - 5.00=- 1.00\space L\).

Step3: Substitute values into the work formula

\(P = 1\space atm\), so \(w=-P\Delta V=-(1\space atm)\times(-1.00\space L)=1.00\space L - atm\).

Step4: Convert units

Since \(1\space L - atm=101.325\space J\), then \(w = 1.00\times101.325\space J\approx101\space J\). The work is positive because the surroundings do work on the system (volume decreases).

Answer:

+101 J