For a photochemical reaction, A B, moles of 'B' were formed on absorption of erg at 360 nm. The quan — Atomic Structure Chemistry Question

💡 Solution & Explanation

Energy absorbed $= 6.626 \times 10^7 \text{ erg} = 6.626$ J. Energy per photon $E = \frac{hc}{\lambda} = \frac{6.626 \times 10^{-34} \times 3 \times 10^8}{360 \times 10^{-9}} = 5.52 \times 10^{-19}$ J. Number of photons absorbed $= \frac{6.626}{5.52 \times 10^{-19}} = 1.2 \times 10^{19}$. Number of molecules of B formed $= 1 \times 10^{-5} \times 6.022 \times 10^{23} = 6.022 \times 10^{18}$. Quantum efficiency $= \frac{6.022 \times 10^{18}}{1.2 \times 10^{19}} \approx 0.5$. Therefore, correct answer is C.