Lifetimes of the molecules in the excited states are often measured by using pulsed radiation source of duration nearly in the nano second range. - Chemistry

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Numerical

Lifetimes of the molecules in the excited states are often measured by using pulsed radiation source of duration nearly in the nanosecond range. If the radiation source has a duration of 2 ns and the number of photons emitted during the pulse source is 2.5 × 1015, calculate the energy of the source.

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Solution

Frequency of radiation (ν),

`"v" = 1/(2.0 xx 10^(9))`

`"v" = 5.0 xx 10^8 " s"^(-1)`

Energy (E) of source = Nhν

Where,

N = number of photons emitted

h = Planck’s constant

ν = frequency of radiation

Substituting the values in the given expression of (E):

E = (2.5 × 1015) (6.626 × 10–34 Js) (5.0 × 108 s–1)

E = 8.282 × 10–10 J

Hence, the energy of the source (E) is 8.282 × 10–10 J.

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Chapter 2: Structure of Atom - EXERCISES [Page 72]

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NCERT Chemistry Part 1 and 2 Class 11
Chapter 2 Structure of Atom
EXERCISES | Q 2.49 | Page 72

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