Material Science- Corrosion is one of the processes that affects the reliability of all engineering components. It is very complicated process and many factors are affecting it. However, when it comes to the fundamentals, it is not as complicated as one think. Basically, corrosion occurs in metals and their alloys because they are with electrons that are not saturated in bond states. Because of this, the work function plays a critical role in determining the corrosion susceptibility of metallic materials.
1) Alternate way of presenting corrosion susceptibility of metals is to compare standard chemical potential of electrons in metals or standard half cell voltage of metals. What is the standard chemical potential of electronics and the standard half-cell voltage? Can you prepare table showing the a few elemental metals and their standard chemical potential as well as half-cell potential?
2) The standard half-cell voltage does indicate whether material in your hand is corrosion prone or not. However, there are a few exceptions on this such as Cr and Al. In case of Cr, its potential is very much in the negative range but is very good at withstanding corrosion (that is a basis of stainless steel). Briefly explain why this is the case.
3) The worst form of corrosion failure is the Galvanic corrosion. Explain what it is and why it is so problematic for the component reliability.
4) Crevice corrosion can be analyzed in the frame work of Galvanic corrosion even if there is no obvious component that can create Galvanic couple with your piece. Briefly explain what type of condition can make Crevice corrosion to be similar to Galvanic corrosion.
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is it possible to convert NO to N2O in our atmosphere? Explain why or why not
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Please answer all numerically with three demical places. :)
A) What is the pH of a buffer prepared by adding 0.405 mol of the weak acid HA to 0.609 mol of NaA in 2.00 L of solution? The dissociation constant Ka of HA is 5.66×10−7.
B) What is the pH after 0.150 mol of HCl is added to the buffer
from Part A? Assume no volume change on the addition of the
acid.
D) What is the pH after 0.195 mol of
NaOH is added to the buffer from Part A? Assume no volume change on
the addition of the base.
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Why is it necessary for scientists to understand chemical reaction rates?
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a. What is the molar solublity of lead(II) chloride in water?
b. Should we be concerned about the chloride ion acting as a base? Why or why not?
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A student mixes 50.0 mL of 1.00 M Ba(OH)2
with 81.2 mL of 0.450 M H2SO4.
Calculate the mass of BaSO4 formed.
Calculate the pH of the mixed solution.
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340.0 gallons of 15.0 M nitric acid were added to a lake. The initial pH of the lake was 6.40 and the final pH was 4.50 . If none of the acid was consumed in chemical reactions, determine the volume of the lake. (IN LITERS)
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When trying to purify fluorene, why does a NaOH extraction work best with Benzoic Acid, succinimide, and fluorenone but a HCl extraction works best with ethyl-4-aminobenzoate? Also, draw the acid/base reaction for each of the reactions.
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1.Please describe how hybridization tells you about chemical structures? What is a good rule of thumb about where groups are arranged around any central atom? Provide a reaction mechanism (i.e. movement of electrons shown) for an organic reaction to illustrate the answer from 1 , and explain how the shape of the molecule changes during a chemical reaction
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The pH change around the equivalence point for strong-base/weak-acid titration is usually not as great as that for strong-base/strong-acid. The statement is true or not. Explain.
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What is the percent yield of dibenzalacetone when 0.212 g of benzaldehyde and 0.058 g of acetone was used in the experiment? I got a 0.885 g of product in the end.
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Show an organic reaction mechanism which relies on bond polarity in order to occur. How does electronegativity participate in this reaction.
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The equilibrium vapor pressure of mercury at room temperature is about 1.6x10-6 atm. Imagine an old chemistry lab that over the years has experienced enough liquid mercury spills and thereby accumulated enough mercury in cracks in the floor, etc. that mercury liquid-vapor equilibrium has been established. What is the concentration, in the units of milligrams per cubic meter, of Hg0 in the air of the room? Does this value exceed the limit of 0.05 mg m-3 established by the American Conference of Governmental Industrial Hygienists (ACGIH) for safe exposure based upon a 40-hour work week?
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