Question

Put two to three iron nails in the blue solution of copper sulphate and after 15 to 20

minutes the colour of the solution turns green. Why?​

Answer 1

Answer

the procedure is known as displacement reaction.the could have been displacement of think by copper and by iron similarly iron could be displaced by copper

Answer 2

PT = y√(1+ cot2 θ )=y√(1+(dx/dy)2 ). Also, PN = y sec q = y√(1+tan2 θ )=y√(1+(dy/dx)2 ). => Length of the normal, PN = |y| √(1+(dy/dx)2 ).