FACTOID # 23: Wisconsin has more metal fabricators per capita than any other state.
 
 Home   Encyclopedia   Statistics   States A-Z   Flags   Maps   FAQ   About 
   
 
WHAT'S NEW
 

SEARCH ALL

FACTS & STATISTICS    Advanced view

Search encyclopedia, statistics and forums:

 

 

(* = Graphable)

 

 


Encyclopedia > Molecular weight

The molecular mass of a substance (less accurately called molecular weight and abbreviated as MW) is the mass of one molecule of that substance, relative to the unified atomic mass unit u (equal to 1/12 the mass of one atom of carbon-12).


The molecular mass can be calculated as the sum of the atomic masses of all the atoms of any one molecule.


The molar mass of a substance is numerically equal to the molecular mass, but expressed in mass units per mole (e.g. grams per mole)

For example: the atomic mass of hydrogen is 1.00784 u and that of oxygen is 15.9994 u; therefore, the molecular mass of water with formula H2O is (2 1.00784 u) + 15.9994 u = 18.01508 u. Therefore, one molecule of water weighs 18.01508 u, and one mole of water weighs 18.01508 grams.

Molecular mass or molar mass are used in stoichiometry calculations.


Since molecules are created by chemical reactions, not nuclear reactions, a molecule's molecular mass exactly equals the sum of the atomic masses of its constituent atoms.


See also

  • Avogadro's number

External links

  • Learning by Simulations (http://www.vias.org/simulations/simusoft_molform.html) Calculation of Molecular Formulas from Molecular Masses

  Results from FactBites:
 
AllRefer.com - molecular weight (Chemistry) - Encyclopedia (569 words)
The molecular weight may be calculated from the molecular formula of the substance; it is the sum of the atomic weights of the atoms making up the molecule.
Molecular weights of substances may be determined experimentally in various ways, the method employed usually depending on the state (solid, liquid, or gas) of the substance.
The molecular weights of substances that are not normally gaseous and do not evaporate without decomposition are sometimes determined from their effects on the melting point, boiling point, vapor pressure, or osmotic pressure of some solvent (see colligative properties).
Molecular mass - Wikipedia, the free encyclopedia (383 words)
The molecular mass of a substance (less accurately called molecular weight and abbreviated as MW) is the mass of one molecule of that substance, relative to the unified atomic mass unit u (equal to 1/12 the mass of one atom of carbon-12).
Molecular mass or molar mass are used in stoichiometry calculations.
Thus the molecular weight of calcium carbonate is 100 therefore the gram-molecular weight is 100 g.
  More results at FactBites »

 
 

COMMENTARY     


Share your thoughts, questions and commentary here
Your name
Your comments

Want to know more?
Search encyclopedia, statistics and forums:

 


Press Releases |  Feeds | Contact
The Wikipedia article included on this page is licensed under the GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m