Redox and qualitative analysis 0.0 / 5 ? ChemistryTransition metalsA2/A-levelOCR Created by: Jalal12362Created on: 04-05-18 20:40 Write the oxidation of Fe2+ to Fe3+ and state the colour change. MnO4- + 8H+ + 5Fe2+ -------> Mn2+ +5Fe3+ + 4H2O Colour change is from purple(MnO4-) to colourless 1 of 5 How is Fe3+ reduced to Fe2+? 2Fe3+ + 2I- ------> 2Fe2+ + 2I2 Orange-brown--------> Pale green, but brown I2 formed 2 of 5 How is chromium reduced? Cr2O72- + 14H+ + 3Zn ------> 2Cr3+ 7H2O + 3Zn2+ Colour change: orange to green 3 of 5 What is the oxidation of Cr3+ to CrO4(2-)? 3H2O2 + 2Cr3+ +10OH- -----> 2CrO4(2-) + 8H2O 4 of 5 Reduction of Cu2+ to Cu+? 2Cu2+ 5 of 5
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