In the photochemical decomposition of ethylene iodide c,h,ly + hv-c,h, +l with radiation of 424 nm, the iodine formed after 20 minutes required 41.14 cm of 0.00

In the photochemical decomposition of ethylene iodide C,H,ly + hv-C,H, +l with radiation of 424 nm, the iodine formed after 20 minutes required 41.14 cm of 0.002 5 mol dm solution of Na,S,O, The intensity of the light source was 0.15 x 10 JsCalculate the quantum yield assuming absorption of the energy was complete.