The iron salt used in blue prints is : — d and f Block Elements Chemistry Question

💡 Solution & Explanation

Step 1: Cyanotype/blueprint processes are based on the light-sensitivity of certain iron(III) complexes. Step 2: Ferric oxalate, Fe2(C2O4)3, is an iron(III) salt that is reduced to iron(II) oxalate upon exposure to light. Step 3: This photoreduction enables the reaction with potassium ferricyanide to form Turnbull's blue/Prussian blue, which creates the blue print. Thus, option (b) is correct.