The energy required to break one mole of hydrogen-hydrogen bonds in H₂ is 436 kJ/mol.What is the longest wavelength of light capable of breaking a single H-H bond? A) 0.474 nm B) 119 nm C) 132 nm D) 274 nm E) 474 nm

Question

Quizplus · Accepted Answer

The energy required to break a single H-H bond can be calculated using the Avogadro constant and the given energy per mole:

E = 436 kJ/mol ÷ 6.022 × 10^23 mol^-1 ≈ 7.24 × 10^-19 J

To find the longest wavelength of light capable of providing this energy, we can use the equation:

E = hc/λ

where h is Planck's constant (6.626 × 10^-34 J·s) and c is the speed of light (2.998 × 10^8 m/s).

Rearranging this equation for wavelength, we get:

λ = hc/E

Substituting the values, we get:

λ = (6.626 × 10^-34 J·s)(2.998 × 10^8 m/s)/(7.24 × 10^-19 J) ≈ 2.74 × 10^-7 m

Converting this to nanometers, we get:

λ ≈ 274 nm

Therefore, the best choice is D, with a wavelength of 274 nm.

The Energy Required to Break One Mole of Hydrogen-Hydrogen Bonds