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A certain amount of an ideal gas occupies a volume of 16 liters at a pressure of 6 atmospheres (atm) and a temperature of 300 \mathrm{~K}. The gas is allowed to expand adiabatically to a final volume of 64 liters. Calculate: Change in enthalpy
 

Option: 1

\mathrm{278 \mathrm{~L}-atm}
 


Option: 2

\mathrm{288 L-atm}


Option: 3

\mathrm{300\: L-atm}


Option: 4

\mathrm{430\: L-atm}


Answers (1)

best_answer

Step 1: Use the ideal gas law to relate the initial and final conditions.

\mathrm{ P V=\eta R T }
Step 2: Calculate the initial and final pressures using the ideal gas law.

\mathrm{ P_1=\frac{n R}{V_1} T_1 }

\mathrm{ P_2=\frac{n R}{V_2} T_2 }

Step 3: Calculate the change in internal energy using the formula for ideal gases.

\mathrm{ \Delta U=\frac{5}{2} n R\left(T_2-T_1\right) }

Step 4: Substitute the given values and calculate the change in internal energy.

\mathrm{ \Delta U=\frac{5}{2} \times(1 \mathrm{~mol}) \times(8.314 \mathrm{~L}-\mathrm{atm} / \mathrm{mol}-\mathrm{K}) \times(300 \mathrm{~K}-300 \mathrm{~K}) }

The change in internal energy \mathrm{ (\Delta U) } for an adiabatic process is zero.

Step 1: Use the formula for change in heat enthalpy \mathrm{ (\Delta H) } for an ideal gas at constant pressure.

\mathrm{ \Delta H=\Delta U+P \Delta V }

Step 2: Calculate the change in volume \mathrm{ (\Delta V) } using the initial and final volumes.

\mathrm{ \Delta V=V_2-V_1 }

Step 3: Calculate the change in heat enthalpy using the calculated values.

\mathrm{ \Delta H=P_2 \Delta V }

Step 4: Substitute the given values and calculate the change in heat enthalpy.

\mathrm{ \Delta H=(6 \mathrm{~atm}) \times(64 \mathrm{~L}-16 \mathrm{~L}) }

Calculating the numerical value of the change in heat enthalpy:

\mathrm{ \Delta H=288 \mathrm{~L}-\mathrm{atm} }

So,Correct option is 2 .
 

Posted by

rishi.raj

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