Not exactly, although they can be. If two molecules are both composed of the same elements, the one that has more atoms in it, the one with more atoms will have a larger molecular mass, and a larger molecular size. However, different elements weigh different amounts.
Take for example the molecule octane, which is an ingredient in gasoline, with formula C8H18. Octane is relatively large, and has a molecular mass of approximately 114 grams per moles. However, a single atom of the element lead, Pb, is much smaller than the molecule octane, and yet the molar mass of lead is 207.2 grams per mole! So it is much heavier, and yet smaller.
On the other hand, hydrogen gas (H2) has a molar mass of 2 grams per mole, and chlorine gas (Cl2) has a molar mass of 71 grams per mole, and Cl2 is indeed much larger than H2.
And so you can see that it depends on the composition of the things you are comparing.
chloroform isCHCl3, and has a molecular mass of 119.5
Molecular mass and formula mass represent the mass of an individual molecule or formula unit of a compound.
The molecular formula is (NH4)2SO4.See the Related Question link to the left for how to find the molecular weight using the molecular formula.
I assume you mean the molecular mass. Its molecular mass is 86.175
I assume you mean the molecular mass. Its molecular mass is 342.3g/mol
The molecular mass of benzene is 78,11.
molecular mass N2o is 44
The molecular mass of cytosine is 111,10.
The molecular mass of glycogen is 666,5777.
molecular mass of P2O5 is 142