Heterocyclic aromatic compounds

Pyridine is more miscible with water than beneze because ...

• it is a non-polar molecule.

• can form H-bonds with water.

• it is a better solvent.

• it is liquid under standard circumstances.

• it is an aromatic compound.

Which is NOT TRUE? Pyridine ...

• is a heterocyclic compound.

• is an aromatic compound.

• is gaseous under standard circumstances.

• has distinctive smell.

• has alkaline solution.

Which is TRUE? Purine ...

• is the mother-compund of cytosine.

• has the molecular formula C₅H₈N₄.

• can be derived from pyridine and imidazole molecules.

• has aromatic structure.

• has the same number of C atoms as benzene.

Which is NOT TYPICAL of pyrrole?

• Its electron system contains 6 electrons.

• Its aromatic electron structure is distorted.

• N atom gives 2 electrons to the aromatic ring.

• It is gaseous under standard circumstances.

• It can react with bromine at room temperature.

Which is TRUE for pyrimidine?

• It is hardly soluble in water.

• It is stronger base than pyridine.

• N atoms are in 1,3 positions.

• Its molecule is non-polar.

• It aromatic structure is built up by 5 electrons.

Which is INCORRECT? Imidazole ...

• is amphoteric.

• has barely higher BP than benzene.

• form H-bonds among its molecules.

• build up enzymes.

• is stronger acid than pyrrole.

Which is badly soluble in water?

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Which contains the most N atoms?

• pyridine

• pyrimidine

• pyrrole

• imidazole

• purine

Which pairing is CORRECT?

• pyridine - haemoglobin

• pyrimidine - guanine

• pyrrole - chlorophyll

• imidazole - cytosine

• purine - amino acid

It contains delocalised electrons.

• pyridine

• pyrimidine

• both of them

• neither of them