WB JEE Medical WB JEE Medical Solved Paper-2008

  • question_answer
    At what temperature will the rms speed of air molecules be double that NTP?

    A)  \[\text{519}{{\,}^{\text{o}}}\text{C}\]                 

    B)  \[\text{619}{{\,}^{\text{o}}}\text{C}\]

    C)  \[\text{719}{{\,}^{\text{o}}}\text{C}\]                 

    D)  \[\text{819}{{\,}^{\text{o}}}\text{C}\]

    Correct Answer: D

    Solution :

                     We have \[{{v}_{rms}}=\sqrt{\frac{3RT}{M}};\]at \[T={{T}_{0}}\](NTP) \[{{v}_{rms}}=\sqrt{\frac{3R{{T}_{0}}}{M}}\] But at temperature \[T,{{v}_{rms}}=2\times \sqrt{\frac{3R{{T}_{0}}}{M}}\] \[\Rightarrow \]               \[\sqrt{\frac{3RT}{M}}=2\sqrt{\frac{3R{{T}_{0}}}{M}}\Rightarrow \sqrt{T}=\sqrt{4{{T}_{0}}}\] or            \[T=4{{T}_{0}}\] \[T=4\times 273\,K=1092\,K\]                 \[\therefore \]  \[T=819{{\,}^{o}}C\]


You need to login to perform this action.
You will be redirected in 3 sec spinner