Question

when magnesium ribbon is dipped into copper sulphate solution the colour of the solution fades away and magnesium ribbon gets coated with the brown layer .
a. name the metal that gets deposited on the surface of the magnesium ribbon.
b.name the reaction that had taken place in the above experiment.
c. represent the reaction in the form of a chemical equation.
d. arrange the following elements in the decreasing order of their reactivity series :
magnesium ,gold ,zinc, potassium. ​

Answer 1

Answer:

a answer is copper

b answer is displacement

CuSO4 + Mg----> MgSO4 + Cu

d answer is potassium then magnesium then zinc then gold

Answer 2

a.

When we dip a magnesium ribbon in the copper sulfate solution, $Mg$ displaces $Cu$ from $CuSO_{4}$ solution.

• This is because $Mg$ is a more reactive element than $Cu$.
• Thus the blue color of the solution fades away.
• And there is a brown coating of copper formed on the magnesium ribbon.

b.

The reaction between copper sulfate solution and magnesium ribbon is said to be a displacement reaction.

• This is because $Mg$ is a more reactive element than $Cu$.
• It displaces $Cu$ from its solution and forms $MgSO_{4}$.

c.

$Mg+CuSO_{4}$  →  $MgSO_{4}+Cu$

• Here $Mg$ displaces $Cu$ from $CuSO_{4}$ solution and forms $MgSO_{4}$ solution.
• This is termed as displacement reaction.

d.

Order of reactivity of the given elements from most reactive to least reactive will be

Potassium > Magnesium > Zinc > Gold

• This is because as we move down the group, the atomic size increases resulting in the decrease of effective nuclear charge.
• As Potassium is larger than magnesium, it can lose its outermost electron easily.
• Hence it is the most reactive element.