Question

Answer the following questions: a. Suppose you have two joined metals (Gold and Copper (II)) immersed in 1MHCl acid, based on the reactants present write possible half cell (anode/cathode) and full cell reaction(s). b. Would corrosion happen in part (a) on its own? Why or why not? c. Would actual corrosion occur if we start bubbling air into the solution? Why or why not? d. How fast is the corrosion occurring?

Answer 1

In an acidic solution of HCl, copper in a Copper (II) and Gold galvanic cell may experience corrosion due to its higher reactivity compared to Gold, which is inert. The introduction of oxygen by bubbling air can enhance corrosion, specifically for copper. The rate of corrosion is dependent on multiple factors and cannot be specified without further data.

Step-by-step explanation:

Galvanic Cell Reactions and Corrosion

When we have two metals like Gold and Copper (II) joined together and immersed in 1M HCl acid, we are setting up a galvanic cell where corrosion could potentially occur. Each metal could theoretically serve as an electrode, with one functioning as the anode and the other as the cathode. In the acidic environment of HCl, copper is more reactive and would tend to act as the anode:

Cathode (reduction): 2H+(aq) + 2e- → H2(g)

Anode (oxidation): Cu(s) → Cu2+(aq) + 2e-

Thus, the full cell reaction would be:

Cu(s) + 2H+(aq) → Cu2+(aq) + H2(g)

In part (a), corrosion could potentially happen on its own between copper and HCl due to the difference in reactivity and the spontaneous nature of the reaction. Gold, being very inert, is unlikely to corrode in this environment. In part (c), bubbling air into the solution introduces oxygen, which can act as an oxidizer, thus increasing the rate of corrosion especially on the copper.

The rate of corrosion can vary based on various factors including the concentration of acid, temperature, the presence or absence of oxidizing agents, and more. Without more specific information, we cannot determine exactly how fast the corrosion is occurring.

Answer 2

The scenario involves two joined metals (Gold and Copper) immersed in 1MHCl acid. The possible half-cell (anode/cathode) reactions are provided along with the full cell reaction. Corrosion would not happen on its own and actual corrosion would not occur if air is bubbled into the solution. The rate of corrosion is zero in this scenario.

Step-by-step explanation:

In this scenario, we have two metals (Gold and Copper) immersed in 1MHCl acid. Based on the reactants present, the possible half-cell reactions are:

Anode: Cu(s) → Cu2+(aq) + 2e-

Cathode: Au3+(aq) + 3e- → Au(s)

The full cell reaction is then:

Cu(s) + 2Au3+(aq) → Cu2+(aq) + 2Au(s)

b. Corrosion would not happen on its own in this scenario because both Gold and Copper are noble metals, which are resistant to corrosion in 1MHCl acid.

c. Actual corrosion would not occur if we start bubbling air into the solution because the presence of oxygen (air) would not affect the corrosion resistance of noble metals like Gold and Copper in 1MHCl acid.

d. Since corrosion is not occurring in this scenario, the rate of corrosion would be zero.