Copy a diagram of one of the chromatographic methods P, T or C shown above into your answerbook - Leaving Cert Chemistry - Question (c) - 2022
Question (c)
Copy a diagram of one of the chromatographic methods P, T or C shown above into your answerbook. Answer part (i) or part (ii) and parts (iii) to (vi) below.
(i) In ... show full transcript
Worked Solution & Example Answer:Copy a diagram of one of the chromatographic methods P, T or C shown above into your answerbook - Leaving Cert Chemistry - Question (c) - 2022
Step 1
In P or T why does the original sample spot S have to be above the solvent level?
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Answer
The original sample spot S must be above the solvent level to ensure that the sample does not dissolve in the solvent immediately. This allows the sample to slowly diffuse and be separated properly as it travels with the solvent front.
Step 2
In C what is the purpose of the glass wool plug?
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Answer
The glass wool plug in column chromatography serves to prevent the stationary phase (solid material) from washing out of the column, ensuring that the separation is effective and the materials remain in place.
Step 3
State what material acts as the stationary phase in the separation you have drawn.
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The stationary phase used in this separation is silica (SiO2) or alumina (aluminum oxide, Al2O3), which provides a solid surface for the separation to occur.
Step 4
Does the mobile phase move up or down through the stationary phase in the separation you have drawn?
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In paper chromatography (P), the mobile phase moves up the paper, while in column chromatography (C), the mobile phase also moves down through the stationary phase.
Step 5
Label with an X on your diagram the component most strongly adsorbed by the stationary phase during the separation.
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Label the component that travels the least distance from the origin as 'X'. This represents the component that is most strongly adsorbed to the stationary phase.
Step 6
Label with a Y on your diagram the component carried fastest by the mobile phase.
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Label the component that travels the furthest from the origin as 'Y'. This represents the component that is carried fastest by the mobile phase.
Step 7
Describe the result you would expect to get if the components of the mixture were all insoluble in the mobile phase.
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If all components of the mixture are insoluble in the mobile phase, there would be no separation observed; all substances would remain at the origin, and no bands or spots would form on the chromatography medium.
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