The first ionization energy of chlorine is 1.25x103 kJ/mol. What is the wavelength of light in units of meters (absorbed) which can ionize a chlorine atom? A. 9.57x10–8 B. 3.13x1015 C. 1.89x1036 D. 3.13x1012 E. 9.57x10–5

The correct option is: A. 9.57 × 10⁻⁸ m

Explanation:

Given:  First molar ionization energy of chlorine (Cl) = 1.25 × 10³ kJ/mol

Since, 1 kJ = 10³ J

∴ First molar ionization energy of chlorine (Cl) = 1.25 × 10³ kJ/mol = 1.25 × 10³ × 10³ J/mol = 1.25 × 10⁶ J/mol

Now, for a single Cl atom,

the first ionization energy of a Cl atom:

Now, to find the wavelength of light absorbed to ionize the Cl atom, we use the Planck equation:

Therefore, the wavelength of light (λ) that can ionize the Cl atom:

Therefore, the wavelength of light (λ) required to ionize a chlorine atom = 9.57 × 10⁻⁸ m