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Assume an ideal gas obeys \mathrm{P V= constant}. This gas confined in a piston-fitted cylinder has an initial volume and pressure of 2 liters and \mathrm{1 \: atm}, respectively, and is allowed to expand to finally occupy 6 liters. Calculate the work done by the system.
 

Option: 1

105 \mathrm{~J}


 


Option: 2

206 \mathrm{~J}
 


Option: 3

110 \mathrm{~J}
 


Option: 4

130 \mathrm{~J}


Answers (1)

best_answer

Step 1: Express \mathrm{P} in terms of \mathrm{V} using the equation \mathrm{PV=constant}

\mathrm{P_1 V_1 =P_2 V_2 }

\mathrm{P_2 =\frac{P_1 V_1}{V_2}}

Step 2: Calculate the work done using the integral.

\mathrm{ W=\int_{V_1}^{V_2} \frac{P_1 V_1}{V} d V }

Step 3: Evaluate the definite integral.

\mathrm{ W=P_1 V_1[\ln |V|]_{V_1}^{V_2} }

Step 4: Substitute the given values and calculate the work.

\mathrm{ W=(1 \mathrm{~atm}) \cdot(2 \text { liters }) \cdot[\ln \mid 6 \text { liters }|-\ln | 2 \text { liters } \mid] }

Calculating the numerical value of the work:

\mathrm{ W \approx(1 \mathrm{~atm}) \cdot(2 \text { liters }) \cdot(1.7918-0.6931) \approx 1.0986 \mathrm{~L} \text {-atm } \approx 105.3 \mathrm{~J} }

So, the work done by the system during this expansion is approximately \mathrm{ 105.3\: joules. }

So, the correct option is 1.

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