Question

What is the standard voltage generated by the corrosion reaction on the iron hull of a ship?
A.-1.676 V
B.-0.782 V
C.1.782 V
D.1.676 V

Answer 1

Hint: As we know that the method of slowly erosion the metal due to moisture and air is named corrosion and therefore the rusting of iron is an example of corrosion. Covering the metal with oil, grease, or paint are often one method to prevent the rusting of iron. Galvanization may be a major process used to prevent corrosion.

Complete step by step answer:
We must remember to prevent the formation of oxides, sulphides, carbonates by the reaction of metal with atmospheric gases, the slow deterioration process should be followed.
This is often referred to as corrosion. One among the foremost common samples of corrosion is that the rusting of iron. Hydrated ferric oxide \[F{e_2}{O_3}.x{H_2}O\] is rust.
Prevention of corrosion is extremely important because enormous damage occurs to buildings, bridges, ships, and everyone other objects made from iron.
In the corrosion process, iron metal acts because the anode during a galvanic cell is oxidised to \[F{e^{2 + }}\], oxygen is reduced to water at the cathode.
This relevant reaction are as follows,
We can write the equation for the reaction takes place at cathode as,
\[{O_{2(g)}} + 4{H^ + }_{(aq)} + 4{e^ - } \to 2{H_2}{O_{(l)}};E_1^ \circ = 1.23V\]
We can write the equation for the reaction takes place at anode as,
\[Fe(s) \to Fe_{(aq)}^{2 + } + 2{e^ - };E_2^ \circ = - 0.45V\]
Overall reaction:
\[2Fe(s) + {O_{2(g)}} + 4H_{(aq)}^ + \to 2Fe_{(aq)}^{2 + } + 2{H_2}O\]
\[{E^ \circ } = E_1^ \circ + E_2^ \circ \]
Substituting the known values in above formula we get,
\[ = 1.23 + 0.45\]
\[{E^ \circ } = 1.68V\]
\[{E^ \circ } \approx 1.676V\]

Therefore, the solution to this present question is option D that’s 1.676V.

Note:
There are two ways preventing corrosion,
Barrier protection: The metal surface is coated with paint which keeps it out of contact with air, moisture, etc. till the paint layer develops cracks. The rusting of iron is often prevented by applying a fill of oil and grease on the surface of the iron tools and machinery since it keeps the iron surface out of contact with moisture, air and carbon-dioxide.
Sacrificial protection: To prevent losing electrons from the iron surface which is covered by the layer of another metal which is more electropositive in nature.
We must remember that the corrosion of metals depends on the reactive nature of metal, presence of air and moisture in surrounding, strain, electrolyte.