What is no average molecular weight?
The number average molecular weight (Mn) measuring system requires counting the total number of molecules in a unit mass of polymer irrespective of their shape or size. This means all molecules are treated equally.
How do you calculate average molecular weight?
To get the number average molecular weight you divide the total weight of the sample by the total number of the molecules.
What is the number average molecular weight?
The number average molecular weight is defined as the total weight of polymer divided by the total number of molecules.
What is the difference between number average and weight average molecular weights?
The key difference between number average and weight average molecular weight is that the number average molecular weight refers to the mole fraction of molecules in a polymer sample whereas the weight average molecular weight is the weight fraction of molecules in a polymer sample.
What is the unit of viscosity average molecular weight?
13.5.1 Molar Mass M is the molar mass, [η] is the intrinsic viscosity or limiting viscosity number. This is obtained by plotting (η – η0)/η0c against concentration c and noting its extrapolated value at infinite dilution. In this case, η is the viscosity of the polymer solution and η0 the viscosity of the pure solvent.
What is considered a high molecular weight?
means a polymer that has a number average molecular weight that is greater than or equal to 1,000 g/mol.
How do you find the average molecular weight of a sample?
This means that you multiply the weight of the molecule by the number of molecules of that weight. For example, there are 13 molecules with a weight of 550,000 so the total weight of molecules with a weight of 550,000 is 13 x 550,00 or 7,150,000.
What is SI unit of viscosity?
Dynamic viscosity: The SI physical unit of dynamic viscosity (μ) is the Pascal-second (Pa s), which is identical to 1 kg m−1 s−1. The physical unit for dynamic viscosity in the centimeter gram second system of units (cgs) is the poise (P), named after Jean Poiseuille. 1 poise = 100 centipoise = 1 g cm−1 s−1 = 0.1 Pa s.
Why do polymers have high molecular weight?
A High molecular weight increases the impact resistance of the material. The higher degree of entanglement means that in order to rupture, more polymer bonds need to be broken, this means that the polymer can absorb more energy before failing. A High molecular weight increases the chemical resistance – to a point.
How do you reduce molecular weight?
Heating and shearing action is the clean way to reduce the molecular weight. You can also try by glycolysis method by heating with glycol or exposing to MW reactor. you will get reduced mol.
What happens when molecular weight increases?
A High molecular weight increases the chemical resistance – to a point. It takes more damage to the main chains of the molecules before it will affect the strength of the material. A High molecular weight increases the viscosity of the material – makes it harder to process the material using conventional methods.
How can you calculate molecular weight?
Calculating Molecular Weight Count how many atoms of each element exist in the molecule. Find the relative atomic mass of each element in the molecule. Calculate the total mass for each element in the molecule. Add up the mass of all the atoms to find the molecular weight.
What is the molar mass of no?
With: NO, its molar mass is 30 because: 14 (there’s 1 nitrogen with atomic mass = 14) + 16 ( there’s 1 oxygen with atomic mass = 16) = 30 g/mol NO2, its molar mass is 46.
What is the atomic mass of no?
Symbol: No Atomic Number: 102 Atomic Mass: (259.0) amu Melting Point: Unknown Boiling Point: Unknown Number of Protons/Electrons: 102 Number of Neutrons: 157 Classification: Rare Earth Crystal Structure: Unknown Density @ 293 K: Unknown Color: Unknown Atomic Structure
How do you calculate the mass of a mole?
Answer Wiki. In order to calculate the mass of one mole of a molecule, we must simply find the atomic weight of each atom in that molecule, multiply each by the number of times it appears, and add them all together.