The ionization enthalpy of hydrogen atom is `1.312 xx 10^6 J mol^-1`. The energy required to excite the electron in the atom from `n= 1` to `n = 2` is :

Options

A. `9.84xx10^(5)J" mol"^(-1)`
B. `8.51xx10^(5)"J "mol^(-1)`
C. `6.56xx10^(5)" J "mol^(-1)`
D. `7.56xx10^(5)J" "mol^-1`

Answer

A

Explanation

`E_(1)=-1.312xx10^(6)" J "mol^(-1)`
`E_(2)=(E_(1))/(2^(2))=-(1.312xx10^(6))/(4)" J "mol^(-1)`
`DeltaE=(E_(2)-E_(1))=1.312xx10^(6)(1-(1)/(4))`
`=(3)/(4)xx1.312xx10^(6)=9.84xx10^(5)` J `mol^(-1)`