## Is it possible to estimate the uncertainty in these measurements?

1.  The Kilogram is now weighed five times on a different scale. The measurements are as follows, in units of micrograms above 1 kg: 25.6, 26.8, 26.2, 26.8, 25.4.

a.   Is it possible to estimate the uncertainty in these measurements? If so, estimate it. If not, explain why not.

b.   Is it possible to estimate the bias in these measurements? If so, estimate it. If not, explain why not.

2.   A new and unknown weight is weighed on the same scale that was used in Exercise 8, and the measurement is 127 μg above 1 kg. Using the information in Exercise 8, is it possible to come up with a more accurate measurement? If so, what is it? If not, explain why not.

3.  The article “Calibration of an FTIR Spectrometer” (P. Pankratz, Statistical Case Studies for Industrial and Process Improvement, SIAM-ASA, 1997: 19–38) describes the use of a spectrometer to make five measurements of the carbon content (in ppm) of a certain silicon wafer whose true carbon content was known to be 1.1447 ppm. The measurements were 1.0730, 1.0825, 1.0711, 1.0870, and 1.0979.

a.   Is it possible to estimate the uncertainty in these measurements? If so, estimate it. If not, explain why not.

b.   Is it possible to estimate the bias in these measurements? If so, estimate it. If not, explain why not.

### Determine the outlet concentration x1 in the water solution and in the trichloroethane solution using an analytical equation.

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### Calculate the minimum solvent that can be used. [Hint: In this case, the tie line through the feed L0 represents the condition for minimum solvent flow rate.

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### Determine the break-point time, the fraction of total capacity used up to the break point, the length of the unused bed, and the saturation loading capacity of the solid.

Drying of Nitrogen and Scale-Up of a Column. Using molecular sieves, water vapor was removed from nitrogen gas in a packed bed (C1) at 28.3°C. The column height was 0.268….