Chemistry 9701 · AS & A Level · States of matter

States of matter — practice question

DNA fingerprinting has grown into a key analytical technique, mainly because it is used to ‘screen’ crime suspects. It is also applied in modern analysis for establishing family relationships, in medicine and in archaeology.
(a(i))[1]

DNA fingerprinting makes use of an analytical technique that you have studied. What is the name of this technique?

(a(ii))[1]

Before DNA fingerprinting can be done, the DNA has to be reduced to shorter lengths of polynucleotides. How is this carried out?

(a(iii))[1]

Which feature of the DNA fragments allows them to move in an electric field?

(b(i))[1]

Use an X on the diagram to show which lines from suspect 1 and suspect 2 do not let you tell which of them was in the house.

(b(ii))[2]

On the basis of this evidence, one suspect was arrested. Which suspect would you expect that to be? Explain your reasoning.

(c)[5]

A sample of a liquid, $P$, was discovered at the scene of the crime and examined by mass spectrometry and NMR spectroscopy. In the mass spectrum, the $M$ and $M+1$ peaks have a ratio of $5.1 : 0.22$, and the $M$ peak is at $m/e = 88$. The NMR spectrum is shown. Use the data to propose a structure for $P$, explaining your answer.

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