The ionisation energy of hydrogen atom is `1.312xx10^(6) J "mol"^(-1)`. Calculate the energy required to excite an electron in a hydrogen atom from the ground state to the first excited state.

Options

A. `9.84 xx 10^5 J mol^(-1)`
B. `8.51 xx 10^5 J mol^(-1)`
C. `6.65 xx 10^5 J mol^(-1)`
D. `7.56 xx 10^5 J mol^(-1)`

Answer

A

Explanation

`DeltaE =E_2 -E_1 = -(1.312 xx 10^6)/(2^2) - (-(1.312 xx 10^(6))/(1^2))`
`= 9.85 xx 10^5 J mol^(-1)`.