MolSynapsequestion bank

MolSynapse / Question bank / Polymers / Molecular mass of polymers

NEET levelSingle correct optionDifficulty 1 of 3pl033

A polymer sample in which every chain has exactly the same molar mass has a polydispersity index $M_{w} / M_{n}$ equal to

Agreater than 1
Bless than 1
C0
D1

Answer: D

If all chains have the same mass,

M_{w} = M_{n}

, so the PDI is exactly 1.

Practice Polymers More on Molecular mass of polymers

Previous questionNext question

More questions on Molecular mass of polymers

A blend contains 10 g of polymer of molar mass 10000 g mol^-1 (one species) and 10 g of polymer of molar mass 40000 g mol^-1 (one species). ... JEE Main level
A sample of polystyrene (repeat unit -[CH2-CH(C6H5)]-, taken as 104 g mol^-1) has M_n = 1.04x10^5 g mol^-1. The number-average degree of pol... JEE Main level
A sample of poly(vinyl chloride), repeat unit -[CH2-CHCl]- (C = 12, H = 1, Cl = 35.5), consists of 120 chains of molar mass 15000 g mol^-1, ... JEE Advanced level
Which statements about molar mass averages of polymers are correct? JEE Advanced level
Which sample is expected to have a polydispersity index closest to 1? JEE Main level
A sample contains 2 mol of chains of molar mass 15000 g mol^-1 and 1 mol of chains of molar mass 45000 g mol^-1. Use M_w = sum N_i M_i^2 / s... JEE Main level