Standard potential question (1 Viewer)

[BlueGas]

How do I know what reaction to use when there are two reduction reactions? For example copper? There are two reactions which involve copper being reduced, how do I know which one to use?

 

[Drsoccerball]

oxidation is higher on the table than reduction therefore the only one above zinc in the given list is manganese and also is the closest to zinc

 

[BlueGas]

oxidation is higher on the table than reduction therefore the only one above zinc in the given list is manganese and also is the closest to zinc

Can you make it more simple? How would you go about answering this question?

 

[Drsoccerball]

Can you make it more simple? How would you go about answering this question?

Okay so its given that the zinc is a cathode therefore the other must be the anode...The anode is any element higher on the potential list than zinc. Therefore we remove the options below zinc. Since the negative sign flips and it becomes positive the one closest to zinc on the potential table would be the anode since it says "Lowest theoretical value"

 

[sharoooooo]

the higher up the table, the easier it is to be oxidised.

therefore, the anode M (where oxidation happens) must be above zinc on the list.

looking at the list, CALCIUM is the highest on the list above Zinc
which means that calcium is oxidised
so we flip/reverse its potential from -2.87V to +2.87V

hence, +2.87 - 0.76 = +2.11
where, -0.76 is the potential for Zinc cathode (which is being reduced so we dont need to flip/reverse its sign)

therefore, calcium is the M anode
not manganese

 

[Drsoccerball]

the higher up the table, the easier it is to be oxidised.

therefore, the anode M (where oxidation happens) must be above zinc on the list.

looking at the list, CALCIUM is the highest on the list above Zinc
which means that calcium is oxidised
so we flip/reverse its potential from -2.87V to +2.87V

hence, +2.87 - 0.76 = +2.11
where, -0.76 is the potential for Zinc cathode (which is being reduced so we dont need to flip/reverse its sign)

therefore, calcium is the M anode
not manganese

Exactly and Manganese and zinc produce a potential of: 0.42 therefore the answers manganese.................since the questions asking for lowest voltage produced
EDIT: and also notice it said galvanic cell if it wrote electrolytical it would be the one closest fro the bottom

 

[sharoooooo]

Exactly and Manganese and zinc produce a potential of: 0.42 therefore the answers manganese.................since the questions asking for lowest voltage produced
EDIT: and also notice it said galvanic cell if it wrote electrolytical it would be the one closest fro the bottom

ohhhh lowest
i am so careless!!

 

[Drsoccerball]

ohhhh lowest
i am so careless!!

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