Shweta Thakur posted an Question
August 12, 2020 • 03:05 am 30 points
  • IIT JAM
  • Chemistry (CY)

Plz explain this question ..i think the answer is b ... ves an absorption line of lowest frequency is a. n=1 to n=2 b. n-3 to n=8 c. n=2 to n=1

Of the following transition in H-atom, the one which gives an absorption line of lowest frequency is A. n=1 to n=2 B. n-3 to n=8 C. n=2 to n=1

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    Ashutosh singh

    Option B, Shweta.

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    Do you remember that wave number formula? Apply that and calculate with both n values.. you'll get the answer. 😊

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    ok sir I have calculated

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    Priyanshu kumar Best Answer

    Option B shweta....as absorption occurs only in 1st and 2nd.. C gives emission line

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    Absorption line in the spectra arise when energy is absorbed i.e., electron shifts from lower to higher orbit, out of a & b, b will have the lowest frequency as this falls in the Paschen series.

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    check this

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    sir

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    Okk😊

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    sorry i have taken 81 square of 9..correct there it is 64..But it is lowest

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    client error aa rha TB se

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    app ka problem rhta hai hmesha🙁

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    got this shweta??

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    I was saying for 1 to 2 energy gap is maximum n and for 3 to 8 gap is minimum right that's why for this frequency is more....because Freq. is directly related to energy

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    shweta for this type of ques...first of check for emissions and absorption case...then for absorption use this formula directly...you get it

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    here shweta absorption case..so we have to use this formula

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    shweta you think it correctly...3 to 8 energy gap.is.minimum then abvious frequency is minimum

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    Here ques asked for lowest frequency not for highest 😊

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    ok ok

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    but sir in my previous question why u have taken emmision case

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    mention to khin koya ni tha

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    there given shweta jumps and one thing...the colour of compound arises not by absorption but by emission

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    when the emitted light energy frequency falls in visible region

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    ok

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    sir thanku

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    always welcome shweta😊

  • comment-profile-img>
    Dinesh khalmaniya 1 best-answer

    option B

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    check it

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    use this formula to calculate frequency

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    out of all options only A, and B give absorption spectrum while C,D give emition spectra

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    check this concept

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    you know E = -13.6/n2 so energy different of n8 to n3 will be lowest while maximum in n1 to n2. so Option B have lowest frequency

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    got it??

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    thanku so much sir

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