JAMB - Chemistry (1988 - No. 10)
A mixture of starch solution and potassium iodide was placed in a test tube. On adding dilute tetraoxosulphate (lV) acid and then K2Cr2O7 solutions, a blue-black colour was produced. In this reaction, the?
iodide is oxidized
tetraoxosulphate (Vl) acid acts as an oxidizing agent
starch has been oxidized
K2Cr2O7 is oxidized