Question

iron knife kept dipped in the blue copper sulphate solution turns the blue solution light green why

Answer 1

The reason is single displacement reaction
iron is more reactive than copper so it displaced copper from copper sulfate solution
thus gradually fading the blue color of copper sulphate and turning green due to formation of iron(II)sulfate

Answer 2

Iron particles go to copper sulphate(turning it green) and copper particles go to iron(turning it brown)

THIS IS THE ACTUAL ANSWER SO MARK BRAINLIEST ✌️