Question

Iron nails were dipped in a blue solution kept in a test tube. After half an hour, it was observed that the colour of the solution has changed to light green. The blue and light green solutions are

• A. copper sulphate and iron sulphate respectively
• B. iron sulphate and copper sulphate respectively
• C. copper and iron respectively
• D. iron and copper respectively

Answer 1

The correct option is A

copper sulphate and iron sulphate respectively

When a few pieces of iron are dropped into a blue solution of copper sulphate, its blue colour slowly changes into light green and also a red substance is formed. The reaction is represented as,

$Iron+\underset{\left(bluesolution\right)}{Coppersulphate}\to \underset{\left(lightgreensolution\right)}{Ironsulphate}+\underset{\left(reddishbrownsolid\right)}{Copper}$