Silica, sio2, is formed on silicon as an electrically insulating layer for microelectronic devices. silica is formed when silico
n is exposed to o2 gas at an elevated temperature. at 900˚c, it takes 90 minutes for the oxygen to diffuse from the surface to form a 0.06 micron (0.06 x 10-6 m) thick layer of sio2 on
1 answer:
Answer:
The question continues; At this same temperature, how long (total time, in minutes) would it take for oxygen to diffuse to form a 0.13 micron thick layer of SiO2? Assume that the silicon can be treated as a semi-infinite solid with a constant concentration of oxygen at the surface. (Hint: What is true of the oxygen concentration at the Si/SiO2 interface?
Explanation:
The application of Grahams law of diffusion comes in; It states that at constant temperature and pressure, the rate of diffusion of a gas is inversely proportional to the square root of its relative molecular mass or the square root of its density.
The detailed step by step explanayion and application of grahams law is as shown in the attachment.
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The addition of sulfate ions shifts equilibrium to the left.
Explanation:
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In this case, according to the following ionization of strontium sulfate:
It is evidenced that when sodium sulfate is added, sulfate, is actually added in to the solution, which causes the equilibrium to shift leftwards according to the Le Ch athelier's principle. Thus, the answer in this case would be:
The addition of sulfate ions shifts equilibrium to the left.
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Answer:
pH = 2.46
Explanation:
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In this case, since this neutralization reaction may be assumed to occur in a 1:1 mole ratio between the base and the strong acid, it is possible to write the following moles and volume-concentrations relationship for the equivalence point:
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So we can divide those moles by the total volume (0.021L+0.0066L=0.0276L) to obtain the concentration of the final salt:
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