CPC Chemical Analysis & Techniques 2

Question 1

In atomic absorption spectroscopy (AAS), what is the primary function of the hollow cathode lamp?

Accepted Answer

To emit radiation at the specific wavelength of the analyte element

Answer

The hollow cathode lamp emits characteristic radiation at the same wavelength absorbed by the analyte element, enabling selective detection.

Question 2

Which chromatographic parameter describes the ability of a column to separate two adjacent peaks?

Accepted Answer

Resolution (Rs)

Answer

Resolution (Rs) quantifies the degree of separation between two adjacent peaks based on their retention times and peak widths.

Question 3

In potentiometry, what does the Nernst equation relate?

Accepted Answer

Electrode potential to ion activity

Answer

The Nernst equation relates electrode potential to the logarithm of ion activity, forming the basis for ion-selective electrode measurements.

Question 4

What is the purpose of an internal standard in quantitative GC analysis?

Accepted Answer

To compensate for sample preparation and injection variability

Answer

An internal standard corrects for variability in sample preparation, injection volume, and instrument response by normalizing peak areas.

Question 5

Which technique measures the mass-to-charge ratio of ions to identify chemical compounds?

Accepted Answer

Mass spectrometry

Answer

Mass spectrometry separates and detects ions based on their mass-to-charge ratio (m/z), providing molecular weight and structural fragmentation data.

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