Physical Chemistry

Mechanics of Materials Lab Experiment #1: Galvanic Corrosion Experiment Objective The object of this experiment is to demonstrate the importance of proper material selection. Various situations will be investigated to determine factors that affect galvanic corrosion.

2. Suppose that an acid flux is inadvertently left on the surface of a silver contact and that in the presence of a thin film of condensed moisture, the acid residue has a pH of 5.0. Under what range of electrode potentials could the corrosion of silver occur in the thin-film electrolyte?

3. Palladium (like gold and platinum) is a noble metal. However, the Pourbaix diagram for pal-ladium (Fig. 6.14) contains a region where palladium is subject to corrosion. Can palladium corrode by the following reaction:

4. The electrode potential of titanium immersed in a sulfuric acid solution of pH approximately 1 was measured to be -0.70 V vs. SCE [21]. (a) Confirm that titanium undergoes active corrosion under these conditions and (b) consult the Pourbaix diagram to suggest three different means to provide corrosion protection.

5. In the interpretation of Pourbaix diagrams, corrosion is considered to occur when the concentration of dissolved metal ions attains a minimum concentration of 1.0 x 10-6 M. Suppose that a 0.50-cm² sample of aluminum immersed in 1.0 L of an aqueous solution corrodes at a constant current density of 100 μA/cm². How long will it take to produce a concentration of 1.0 x 10-6 MAI³+?

6. Calculate the standard reduction potential Eº for the reaction

Q2: A tin can immersed in seawater shows a current density of 2.45 x 10-6 A/cm². What is the rate of corrosion in mg/dm²/day (mdd)? Atomic weight of tin is 118.69 g/mol.

VOLUMETRIC ANALYSIS THE TITRATION OF ACIDS AND BASES Objective: To determine the molarity of the acetic acid solution by titrating with the standardized solution of the sodium hydroxide by volumetric analysis.

Q5: A mild steel cylindrical tank 1 m high and 50 cm dia contains aerated water to the 60 cm level and shows a loss in weight due to corrosion of 304 g after 6 weeks. Calculate the corrosion current density involved. Assume atomic weight of steel is 55.85 g/mol.

Chapter Four-Homework As stated in the syllabus: You are expected to write your answers neatly and legibly. You will receive zero credit if the instructor/grader cannot read your work no partial credit is given. You are always free to type your assignment using word or other programs. All written solutions must be provided with a clear sentence structure (subject, verb, and object). Mathematical answers must be coherent and you need to show as many steps in your work as you can. The final answer to a problem must be boxed and numerical answers must have the correct units. Failure to do so, even if it is correct, will result in a loss of credit. Cumulative Review