Term
| the difference between accuracy and precision |
|
Definition
Accuracy
agreement of a measurement with actual value
Precision
refers to reproducibility of a measurement |
|
|
Term
| measurements are caused by unknown and unpredictable changes in the experiment. These changes may occur in the measuring instruments or in the environmental conditions. |
|
Definition
|
|
Term
observations usually come from the measuring instruments.
They may occur because:
•there is something wrong with the instrument or its data handling system, or
•because the instrument is wrongly used by the experimenter |
|
Definition
|
|
Term
|
Definition
When rounding examine the digit to the right of the digit that is to be last (this number is called the trigger):
a) if the trigger is less than 5, drop it and all the digits to the right of it
b) if the trigger is more than 5, increase by 1 the number to be rounded
c) if the trigger is 5, round the number so that it will be even |
|
|
Term
|
Definition
|
|
Term
| is a broad range of physical methods used to separate and or to analyze complex mixtures. |
|
Definition
|
|
Term
|
Definition
For paper chromatography the rf value is the ratio the spot moved compared to the distance the solvent moved from the starting point. Rf=0, Rf=1
Rf=distance spot moved/distance solvent moved |
|
|
Term
| how do you choose a good solvent as a mobile phase for solid/liquid chromatography |
|
Definition
| In these (and all types of) chromatographies, a mixture is separated by distributing the components between a stationary phase and a mobile phase. The mixture is first placed on the stationary phase (a solid or a liquid) and then the mobile phase (a gas or a liquid) is allowed to pass through the system. |
|
|
Term
| what happens in any absorption spectroscopy |
|
Definition
| the concentration and structure of a substance by measuring the intensity of electromagnetic radiation it absorbs at various wavelengths |
|
|
Term
| maximum absorbance in the visible range |
|
Definition
•Violet:400 - 420 nm
•Indigo:420 - 440 nm
•Blue:440 - 490 nm
•Green:490 - 570 nm
•Yellow:570 - 585 nm
•Orange:585 - 620 nm
•Red:620 - 780 nm |
|
|
Term
|
Definition
|
|
Term
A = log10 P0 / P
A = log10 1 / T
A = log10 100 / %T
A = 2 - log10 %T |
|
Definition
|
|
Term
|
Definition
|
|
