Question

You have 3 metals and salt solutions of these metals. Test
tube Solution

A	Magnesium sulphate
B	Copper sulphate
C	Ferrous sulphate

When you were away, your younger brother added a metal in a blue coloured solution to make it green. Which of the following could have happened?

• A. Iron fell in A
• B. Magnesium fell in C
• C. Iron fell in B
• D. Magnesium fell in B

Answer 1

The correct option is C Iron fell in B

Copper sulphate solution is a blue coloured solution. Iron and magnesium are both more reactive than copper.

If iron falls in a solution of copper sulphate it replaces the copper ions and forms ferrous sulphate which is green in colour.

If magnesium falls in the solution of copper sulphate it also replaces the copper ions and forms magnesium sulphate which is colourless.