Question

how to calculate the molecular weight if the molar volume and the specific volume are given

Answer 1

Consider specific volume is measured in units of:\[\frac{m^3}{kg}\]
Molar Volume is measured in \[\frac{m^3}{mol}\]
You want kg/mol so you want:
\[\frac{molar weight}{specific weight}\]
This gets you \[\frac{kg}{mole}\]
You may need to play with units to get the desired units i.e. g/mol.

Answer 2

It you write out the units for molar weight and divide them by the units for specific weight you will see the m^3 cancel. Then times the units by kg/kg and mol/mol to get the units in the correct orientation.

Answer 3

I get it thanks

Answer 4

gotta a problem with the units

Answer 5

a sample has a specific volume of 5.2 (m^3)(1/kg) and a molar volume of 1160 (m^3)(kg*1/mol) determine the molecular weight of the material

Answer 6

I think they may have supplied incorrect units, see: http://en.wikipedia.org/wiki/Molar_volume.
\[\frac{1160\frac{m^3}{mol}}{5.2\frac{m^3}{kg}}\frac{kg}{kg}\frac{mol}{mol}=2.2*10^2\frac{kg}{mol}\]