Not exactly.
Strictly speaking molar or molecular mass is reserved for compounds with discrete molecules. Most of these tend to be covalent compounds like H2O (water) or CH4 (methane).
Formula mass is a more general term which includes substances like NaCl (Sodium chloride), which are ionicly bonded crystals in the solid state. There are no "molecules of NaCl."
For crystals such as hydrates, formula mass also allows of substances like CuSO4*5H20 ( Copper sulfate pentahydrate) to be used in calculating reaction ingredients.
In either case, these "masses" can be used for the calculation of the number of moles of a substance used or formed in a chemical reaction (provided ones knows the balanced equation).
2006-09-27 14:22:16
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answer #1
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answered by Richard 7
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Yes. The reason that some texts, teachers etc use the term formula mass is that molar mass is strictly not a good description of say an ionic substance because they exist as an extended lattice of cations and anions rather than discrete molecules. A similar situation occurs with giant covalent substances such as SiO2.
2006-09-27 21:19:40
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answer #2
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answered by Auriga 5
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Yes.
The "molar mass" is a general term, which includes the subcategories of "formula mass", used for ionic compounds, and "molecular mass", used for molecular mass.
It is a less descriptive term (ie: it does not tell you if the chemical is ionic or molecular), but the number means the same thing, which is "grams per mole" for that chemical.
I have given you the exact and only correct answer so far. All the others are confused.
The college prof is right, but is not telling you the entire answer (ie: not telling you enough about molecular mass)
2006-09-27 21:36:29
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answer #3
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answered by MrZ 6
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I think that molar mass the mass of one avagadros number and element or compound. The molar mass of one avagadros number of carbon is 12.011.
2006-09-27 21:25:26
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answer #4
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answered by T & A 1
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