Haryana PMT Haryana PMT Solved Paper-2005

  • question_answer
    One mole of an ideal gas is initially at \[{{0}^{o}}C\] and \[1atm\]pressure. If it absorbs 1000 cal heat during a reversible isothermal expansion, what will be its final volume?

    A)  \[102.5litre\]   

    B)  \[242.5litre\]

    C)  \[22.4\text{ }litre\]                        

    D)  \[121.25\text{ }litre\]

    Correct Answer: A

    Solution :

                    Since the gas is under S.T.P conditions, Hence \[{{V}_{1}}=22.4\] litre,  \[{{V}_{2}}=?\] For isothermal and reversible expansion, \[\Delta E=0\] \[\therefore \]  \[q=-W\]                 \[=-[-nRT\times 2.303\log \,\,\,{{V}_{2}}/{{V}_{1}}]\] or            \[100\times 4.184\,J=1\times 8.314\times 273\]                                 \[\times 2.303\times \log \frac{{{V}_{2}}}{22.4}\] or            \[4184=5227.17\,\log \frac{{{V}_{2}}}{22.4}\]      or            \[\frac{{{V}_{2}}}{22.4}=\text{antilog}\,\,\text{0}\text{.8004}\]                 \[{{V}_{2}}=121.25ml\]


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