Chromatography Review

In paper chromatography how would you know the substance or mixture was insoluble in the mobile phase used?

• The substance would as far as the mobile phase did

• The substance would only move a short distance on the paper

• The substance would remain on the baseline and not move.

• Solubility cannot be determined through chromatography

Determine which statement is true:

• This is a chromatogram of a pure substance

• In this chromatogram all of the substances have relatively equal attractions to the stationary phase

• This is a chromatogram of a mixture with three components having equal amounts in the mixture

• This is a mixture with three components that each have different amounts present in the sample

Which ink sample looks like a pure substance. (Use the letters below the baseline to identify the inks)

• Bc

• Br

• G

• O

Tags

NGSS.HS-PS1-3

A substance is determined to have an Rf value equal to 0.33. What can be determined from this value?

• The substance is insoluble

• The substance is highly attracted to the mobile phase

• The substance is very attracted to the stationary phase

• The substance is equally attracted to the mobile and stationary phases

In both HPLC and GC analysis, what important process occurs inside the column?

• The different components of the mixture separate from each other

• The substance is quantified by its absorbance of light/radiation

• The sample is introduced into the chromatography system

• The substance interacts with the mobile phase for the first time.

What is the retention time of the peak present in the greatest quantity?

• 3.5 minutes

• 4.1 minutes

• 4.5 minutes

• 7.7 minutes

What substance is exclusively located in the column of HPLC and GC systems?

• The mobile phase

• The stationary phase

• The detector

• The substance being analyzed

Which is the correct equation for calculating an Rf value?

• Distance of Mobile phase/distance of substance

• Time in mobile phase/time is stationary phase

• distance of substance/distance of mobile phase

• Baseline/solvent front

In order for a substance to move quickly through a column in HPLC/GC analysis it must be highly attracted to the __________.

Which of the following is the best description for what occurs inside the detector in HPLC/GC analysis:

• The substances all pass through at the same time and absorb or reflect light/radiation

• The substances pass through one at a time and reflect light/radiation

• The substances pass through one at a time and absorb light/radiation based on how much of the substance is present

• The substances pass through the detector all at the same time and absorb light/radiation depending on how much substance is present

Tags

NGSS.HS-PS4-3