Question

The energy required to excite the electron in the atom from n=1 to n=2, when the ionisation enthalpy of hydrogen atom is \(1.312 \times 10^6\) J/mol will be (in the unit of \(10^5\))

• A. 8.53
• B. 7.51
• C. 8.92
• D. 9.86

Hint:

When dealing with ionisation enthalpy, divide by 2 for the energy required to excite from n=1 to n=2.

Answer 1

The Correct Option is D

The energy required to excite the electron can be calculated using the ionisation enthalpy and the relation: \[ \Delta E = \frac{1.312 \times 10^6}{2} = 6.56 \times 10^5 \, {J/mol} \] Converting this into \(10^5\) J: \[ {Energy} = 9.86 \times 10^5 \, {J/mol} \] Thus, the correct answer is (d) 9.86.