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For a hydrogen atom, the ionization enthalpy is 1.312 × 10⁶ J mol⁻¹. What amount of energy is needed to raise the electron from the ground state (n = 1) to the first excited state (n = 2)?
- 8.51 × 10⁵ J mol⁻¹
- 6.56 × 10⁵ J mol⁻¹
- 7.56 × 10⁵ J mol⁻¹
- 9.84 × 10⁵ J mol⁻¹
Correct answer: 9.84 × 10⁵ J mol⁻¹
Solution
Energy to go n=1 to n=2 = 1.312e6 x (1 - 1/4) = 1.312e6 x 0.75 = 9.84e5 J/mol. The stored 6.56e5 is wrong.
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