Question

Question 5 (2 points) For which of the following compounds will the M+2 peak intensity be equal to the intensity of the molecular ion peak M? a) CH3CH2CH OH 0 b) CHỊCH CHANH, Oc) CH3CH2CH_Br d) CH,CH2CH2C1 Question 6 (2 points) What is the product of the reaction below? "OH PCC o OH O OH TV a) Obiy c)

Answer 1

Answer-5: (c) Bromopropane.

The M+2 peak in a mass spectrum arises from the presence of chlorine or bromine atoms in an organic compound. Bromine has two isotopes, 79Br and 81Br in an approximately 1:1 ratio.

That means that a compound containing 1 bromine atom will have two peaks in the molecular ion region, depending on which bromine isotope the molecular ion contains.

If Chlorine is present, its two isotopes are present in 3:1 ratio, which gives a remarkable difference in height and intensity of peaks.

Unlike compounds containing chlorine, though, the two peaks will be very similar in height in bromine.

Hence, the correct answer is option (c) : Bromopropane.

Answer-6:

PCC is a mild oxidizing agent. It oxidises primary alcohol into aldehyde and secondary or tertiary alcohol into ketone.

Here, primary alcohol is present, therefore, would be converted into aldehyde.

Hence, the correct answer among all is option (a): 1.