From a copper transformation experiment, copper (II) sulfate solution was prepar

Question

From a copper transformation experiment, copper (II) sulfate solution was prepared after several different reactions then zinc powder was added to it.

The question afterwards relative to that portion of the experiment is:

Zinc metal is added to Copper(II) to undergo a redox reaction

Zn + Cu^2+-> Cu + Zn^2+

Hydrogen gas was also formed in this step. How? Why was a large excess of zinc added in this step?

Was it just reacting with unreacted sulfuric acid used to prepare the copper sulfate previously?

Explanation / Answer

Solution :-

Balanced redox reaction is

Zn + Cu^2+-> Cu + Zn^2+

In this step the Zn is reducing the Cu^2+ ions into the solid Cu element

Therefore to ensure all the Cu^2+ gets reduced from the reaction and recovered as solid Copper we need to use excess Zn so that reaction goes to the completion and all the Cu^2+ ions gets reduced to Cu and gives the maximum recovery of the Cu.

It is also used to react with the H2SO4 and by the reaction it produces the H2 gas and ZnSO4(aq) which remain in the solution in the form of ions.

Related Questions

Navigate

• Browse (All)
• Browse F
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.