Question

Obtaining copper sulfate from copper oxides by using sulfuric acid is a:
(A)- redox reaction
(B)- neutralization reaction
(C)- displacement reaction
(D)- both A and B

Answer 1

Copper sulfate is produced by treating copper metal with hot and concentrated sulfuric acid or copper oxide with dilute sulfuric acid. Copper sulfate used in commercial purposes is usually about 98% pure copper sulfate, and may contain traces of water.

Complete step by step answer:

Copper sulfate can be easily made by the reaction of Copper oxide and dilute sulfuric acid in laboratory by using a simple method as follows:
- First of all, add dilute sulfuric acid into a beaker and heat using a Bunsen burner flame.
- Add copper (II) oxide, a little at a time to the warm dilute sulfuric acid and until the copper (II) oxide is excess i.e. the copper (II) oxide stops mixing with the warm sulfuric acid.
- Now to remove the excess copper (II) oxide filter the mixture into an evaporating basin.
- Leave the filtrate in a warm place and let it dry and crystallize.
- Decant excess solution after the copper (II) sulphate is crystallized.
- Dry the remaining copper (II) sulphate crystals.
The chemical reaction for obtaining copper sulphate from copper oxides by using sulfuric acid can by written as the following:
$CuO(s) + {H_2}S{O_4}(aq) \to CuS{O_4}(s) + {H_2}O(l)$
As we can see, the oxidation state of copper oxide in the left side of reaction is -2 but overall copper oxide is neutral therefore the charge on copper is +2. Similarly, on the right side of reaction, the oxidation state of copper is +2. Since the oxidation state of copper didn’t change in the above reaction, therefore this is not a redox reaction.
Now, in this reaction we can see that the oxygen is replaced by sulphate i.e. oxygen is displaced by sulphate molecule. Therefore, the above reaction is a displacement reaction.

So, the answer of the above question is (C)- displacement reaction.

Note: You should be very careful while checking for the neutralization of reaction. Copper sulphate is a salt of a strong acid and a weak base therefore the resultant salt is an acidic salt not a neutral salt. Similarly, the reaction of any strong base and weak acid will result in a basic salt.