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### Topic: analytical pre-exam questions  (Read 1840 times)

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#### VKT

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##### analytical pre-exam questions
« on: February 13, 2023, 08:46:52 AM »
Hi there,

I am struggling to answer the questions bellow. Could anyone suggest any kind of answer? My exam is tomorrow and i still haven´t figure out how to solve them.

1.Explain the difference between the standard deviation starting from the population, and the standard deviation starting from samples, and write down the corresponding formulas!

I know the formulaas and the only explanation i can think is by which corresponding faktor they are being divided by. But isn´t there another reason?

If the set of values is seen as its own population, then we divide by the number of values N.
If the set of values is a sample of a larger population, we divide by one less than the number of values in the sample, i.e. n-1.

2.Explain the advantages and disadvantages of reflective optics compared to transmission optics. Name one spectroscopic method each as an example and justify why you would work with reflective or transmission optics there!
For this one i don´t know where to start off

I thought of AAS. But i am not sure it is correct

4.Your task is to analyze the iron content of ore on a conveyor belt. Discuss in principle different approaches and considerations, possible problems and different analytical solutions!
For this one i am also not sure how to tackle it.

5.Explain each of two methods for elemental analysis that you can use when a) the sample quantity is largely unlimited or b) when very little sample material is available.
This i also don´t know where to look for answers.

6. The differentiation of enantiomers is of great importance, especially in pharmaceutical analysis. Name and EXPLAIN two fundamentally different procedures!
Here i thought of Refractive index, but a second one does not come to my mind.

Thank you,
Best Regards VKT
« Last Edit: February 13, 2023, 10:35:21 AM by VKT »

#### Corribus

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##### Re: analytical pre-exam questions
« Reply #1 on: February 13, 2023, 10:19:27 AM »