Q23 / 105 · JEE Main 2008 · Chemistry
The ionization enthalpy of hydrogen atom is $1.312 \times 10^6 \mathrm{Jmol}^{-1}$. The energy required to excite the electron in the atom from $n=1$ to $n=2$ is
- A$8.51 \times 10^5 \mathrm{Jmol}^{-1}$
- B$6.56 \times 10^5 \mathrm{Jmol}^{-1}$
- C$7.56 \times 10^5 \mathrm{Jmol}^{-1}$
- Correct answerD$9.84 \times 10^5 \mathrm{Jmol}^{-1}$
Solution
$$
\begin{aligned}
& \Delta \mathrm{E}=\mathrm{E}_2-\mathrm{E}_1=-\frac{1.312 \times 10^6}{2^2}-\left(-\frac{1.312 \times 10^6}{1}\right) \\
& =9.84 \times 10^5 \mathrm{~J} \mathrm{~mol}^{-1}
\end{aligned}
$$
Hence, the correct answer is option: 'D'.