Question

Study the type of chemical reaction taking place when zine metal reacts with copper sulfate and complete the observation and conclusion.

Things needed: A beaker, zinc metal, copper sulfate solution.

Method:

• Take copper sulfate solution (sky blue color) in a beaker and add Zinc metal to it.•
• Notice the change and complete the observation given below.

Observation : (i) Colour changes from sky blue to ........

(ii) The reaction is ................. (exothermic or endothermic).

(iii) ........ metal precipitated as solid.

(iv) Type of reaction ...........

Conclusion: Chemical equation is $\mathrm{Zn}+{\mathrm{CuSO}}_4\to$

Answer 1

Displacement reaction: A displacement reaction is one in which the atom or a set of atoms is displaced by another atom in a molecule. For example, when the iron is added to a copper sulfate solution, it displaces the copper metal.

$\mathrm{A}+\mathrm{B}-\mathrm{C}\to \mathrm{A}-\mathrm{C}+\mathrm{B}$

The above equation exists when A is more reactive than B.

• Adding Zinc($\mathrm{Zn}$) to Copper sulfate(${\mathrm{CuSO}}_4$) solution results in the formation of Zinc sulfate(${\mathrm{ZnSO}}_4$) and Copper($\mathrm{Cu}$).
• It is a type of displacement reaction.
• $\underset{\mathrm{Zinc}}{\mathrm{Zn}\left(\mathrm{s}\right)}+\underset{\mathrm{Copper}\mathrm{sulfate}}{{\mathrm{CuSO}}_4\left(\mathrm{aq}\right)}\to \underset{\mathrm{zinc}\mathrm{sulfate}}{{\mathrm{ZnSO}}_4\left(\mathrm{aq}\right)}+\underset{\mathrm{Copper}}{\mathrm{Cu}\left(\mathrm{s}\right)}$
• Initially, Copper sulfate(${\mathrm{CuSO}}_4$) is blue in color and after the chemical reaction Zinc sulfate(${\mathrm{ZnSO}}_4$) is formed which is colorless.
• Copper is obtained in form of precipitates
• Exothermic reaction: It is the type of reaction in which energy is released.
• For example: $\underset{\mathrm{Magnesium}}{2\mathrm{Mg}\left(\mathrm{s}\right)}+\underset{\mathrm{Oxygen}}{{\mathrm{O}}_2\left(\mathrm{g}\right)}\stackrel{\mathrm{Heat}}{\to }\underset{\mathrm{Magnesium}\mathrm{oxide}}{2\mathrm{MgO}\left(\mathrm{s}\right)}+\mathrm{heat}$
• Endothermic reaction: It is the type of reaction in which energy is absorbed.
• For example, $\underset{\mathrm{Calcium}\mathrm{carbonate}}{{\mathrm{CaCO}}_3\left(\mathrm{s}\right)}\stackrel{\mathrm{heat}}{\to }\underset{\mathrm{Calcium}\mathrm{oxide}}{\mathrm{CaO}\left(\mathrm{s}\right)}+\underset{\mathrm{Oxygen}}{{\mathrm{O}}_2\left(\mathrm{g}\right)}$

Observation : (i) Colour changes from sky blue to colorless.

(ii) The reaction is exothermic (exothermic or endothermic).

(iii) Copper metal precipitated as solid.

(iv) Type of reaction displacement

Conclusion: Chemical equation is $\underset{\mathrm{Zinc}}{\mathrm{Zn}\left(\mathrm{s}\right)}+\underset{\mathrm{Copper}\mathrm{sulfate}}{{\mathrm{CuSO}}_4\left(\mathrm{aq}\right)}\to \underset{\mathrm{zinc}\mathrm{sulfate}}{{\mathrm{ZnSO}}_4\left(\mathrm{aq}\right)}+\underset{\mathrm{Copper}}{\mathrm{Cu}\left(\mathrm{s}\right)}$