121.

The poly dispersity index (PDI) of a polymer is ($\stackrel{-}{\mathrm{M}}$_w = weight average molecular mass and $\stackrel{-}{\mathrm{M}}$_n = number average molecular mass)

• the product $\stackrel{-}{{\mathrm{M}}_{\mathrm{n}}} \mathrm{and} \stackrel{-}{{\mathrm{M}}_{\mathrm{w}}}$

• the sum of $\stackrel{-}{{\mathrm{M}}_{\mathrm{n}}} \mathrm{and} \stackrel{-}{{\mathrm{M}}_{\mathrm{w}}}$

• the difference between $\stackrel{-}{{\mathrm{M}}_{\mathrm{w}}} \mathrm{and} \stackrel{-}{{\mathrm{M}}_{\mathrm{n}}}$

• the ratio between $\stackrel{-}{{\mathrm{M}}_{\mathrm{w}}} \mathrm{and} \stackrel{-}{{\mathrm{M}}_{\mathrm{n}}}$

The monomers of buna-S rubber are

• lsoprene and butadiene

• Butadiene and phenol

• Styrene and butadiene

• Vinyl chloride and sulphur

The structure of Nylon–6 is:

Which of the following compounds is a constituent of the polymer?

[-HN-CO-NH-CH₂-]_n

• Ammonia

• Methylamine

• Formaldehyde

• N-methyl urea

Which of the following is a condensation polymer?

• Buna-S

• Teflon

• Nylon 6,6

• Neoprene

The major product of the following reaction is:

The correct match between item – I and Item –II is

• a-III,b-I, c-II,d-IV

• a-II, b-IV, c-II, d-IV

• a-IV, b-IV, C-I, d-III

• a-III, b-I, c-IV, d-II