If an Einstein $(E)$ is the total energy absorbed by $1$ mole of a substance and each molecule absorbs one quantum of energy, then calculate the value of ' $E (i n e r g s)$ ' in terms of $λ$ in $c m$ .

Open in App

Solution

Total Energy=EJ/mol
energy of one molecule $E^{''} = \frac{E}{N_{A}} (N_{A} =$ avogrado number)
$E^{''} = \frac{h c}{λ_{(m)}} = \frac{E}{N_{A}} λ_{(m)} = \frac{h c}{E} \times N_{A} λ_{(m)} = \frac{100 h c \times N_{A}}{E}$
$E = \frac{100 \times 6.67 \times 10^{- 34} \times 6.022 \times 10^{23}}{λ}$
$E = \frac{12.05}{λ} J$
But $1 J = 10^{7} e r g s$
$∴ E = \frac{1.205 \times 10^{8}}{λ} e r g s$

Suggest Corrections

Similar questions

Q. One molecule of a substance absorbs one quantum of energy. The energy involved when

1.5

mole of the substance absorbs red light of frequency

7.5 \times 10^{14}

s e c^{- 1}

will be:

Iodine molecule dissociates into atoms after absorbing light of 4500A∘A∘.If one quantum of radiation is absorbed by each molecule,calculate the kinetic energy of iodine atoms (Bond energy of I2=240KJmol−1

Q. Iodine molecule dissociates into atoms after absorbing light of 4500

o A

. If one quantum of radiation is absorbed by each molecule. Calculate the kinetic energy of iodine atoms (bond energy of

I_{2} = 240 k J m o l^{- 1}

)

One mole of photons is known as one Einstein of radiation. According to Stark-Einstein law of photochemical equivalence, one mole of reactant absorbs one Einstien of energy. For a photochemical reaction, a term called quantum yield is defined as:
Quantum yield $(ϕ) = \frac{N o . o f m o l e s o f r e a c t a n t c o n v e r t e d}{N o . o f E i n s t e i n a b s o r b e d}$
The correct statement(s) is/are:

Q. One quantum is absorbed per gaseous molecule of Br

_{2}

for converting into Br atoms. If light absorbed has wavelength 5000 A, calculate energy required in KJ/mol.

Join BYJU'S Learning Program

If an Einstein (E) is the total energy absorbed by 1 mole of a substance and each molecule absorbs one quantum of energy, then calculate the value of 'E(in ergs)' in terms of λ in cm.

Total Energy=EJ/molenergy of one molecule E′′=ENA(NA=avogrado number)E′′=hcλ(m)=ENAλ(m)=hcE×NAλ(m)=100hc×NAEE=100×6.67×10−34×6.022×1023λE=12.05λJBut 1J=107 ergs∴E=1.205×108λ ergs

If an Einstein $(E)$ is the total energy absorbed by $1$ mole of a substance and each molecule absorbs one quantum of energy, then calculate the value of ' $E (i n e r g s)$ ' in terms of $λ$ in $c m$ .