Respuesta :
Answer:
For a: The balanced chemical equation is written below.
For b: The corrosion of iron pipe will take place in the presence of zinc.
For c: Zinc will not protect iron pipe from corrosion.
Explanation:
- For a:
The given half reaction follows:
The substance having highest positive [tex]E^o[/tex] potential will always get reduced and will undergo reduction reaction. Here, zinc will undergo reduction reaction will get reduced.
Oxidation half reaction: [tex]Zn\rightarrow Zn^{2+}+2e^-;E^o_{Zn^{2+}/Zn}=-0.763V[/tex]
Reduction half reaction: [tex]Fe+2e^-\rightarrow Fe;E^o_{Fe^{2+}/Fe}=-0.441V[/tex]
The balanced chemical equation follows:
[tex]Fe+Zn^{2+}\rightarrow Fe^{2+}+Zn[/tex]
- For b:
For a reaction to be spontaneous (thermodynamically feasible) , the standard electrode potential must be positive.
To calculate the [tex]E^o_{cell}[/tex] of the reaction, we use the equation:
[tex]E^o_{cell}=E^o_{cathode}-E^o_{anode}[/tex]
Substance getting oxidized always act as anode and the one getting reduced always act as cathode.
Calculating the [tex]E^o_{cell}[/tex] using above equation, we get:
[tex]E^o_{cell}=-0.441-(-0.763)=0.322V[/tex]
As, the EMF is coming out to be positive, the reaction will be thermodynamically feasible and corrosion of iron pipe will take place in the presence of zinc.
- For c:
As, the EMF of the cell is positive, the zinc will not protect the iron pipe from corrosion and the reaction will take place.
