I spot homework.
moles = mass/mr
You want mr (molecular mass) so we rearrange using algebra.
mr = mass/moles
Now we plug in your numbers. Luckily the units are already correct.
mr = 119.3/2.13
I'll allow you to get your calculator (or use windows calculator) and finish it off.
109.9 grams/0.696 moles = 157.9 grams per mole.
moles = weight in grams / molecular weight = 56 / 28 = 2 moles
Multiply the number of moles by the molecular weight of the compound (or atomic weight for an element) to find the mass in grams.
See the Related Questions to the left of this answer:"How do you convert from grams to moles and also from moles to grams?"
C6H6 is the molecule of benzene and it's molecular weight is 78, calculated as 6 x 12 +6 x 1=78 and you will understand it if you know some basics of chemistry. then, You know that each mole of a molecule weighs exactly those number of grams as much as is its molecular weight. That means if a molecule has 'M' as its molecular weight, then one mole of it weighs exactly M grams when actually weighed using a weighing machine. This means one mole of benzene weighs 78 grams. then 195 grams of C6H6 has (1/78)x195 moles or 195/78 moles in it.
Multiply the number of moles by the molecular weight.
Because the formula for calculating moles is dividing grams by the molecular weight. The molecular weight for glucose is 180. grams to moles is also the same as milligrams to millimoles.
molecular weight
the answer to your question is 0.0004 g/mol.
For these conversions, you need the atomic masses of the elements involved in grams. If it is just one element, then you use the atomic mass, but if its a compound, then use the molecular mass (added atomic masses). Take the number of moles and multiply it by the atomic (molecular) mass to get number of grams.
Multiply the # of grams by the element's atomic weight. Or if dealing with milliliters, multiply the volume by solutions molarity. When calculating a molecule's # of moles, multiply the # of grams by the molecular weight.
You first divide the amount of molecules by avagadros number (6.022x10^23) to find out how many moles you have. Then you find out the molecular weight of the compound. You multiply the number of moles by the molecular weight to give you your weight in grams.