Relation between molecular mass and molar mass

In summary, molecular mass refers to the mass of one molecule of a substance, while molar mass refers to the mass of one mole of a substance. They are related by multiplying the molecular mass by the number of molecules in a mole, but the units for molar and molecular mass must be taken into consideration. Molar mass is measured in grams per mole (gmol-1), while relative molecular mass is another term for molecular mass.
  • #1
rubenhero
42
2

Homework Statement



What is the difference between molecular mass and molar mass? Are they related?

Homework Equations



moles = total mass/ mass/mole

The Attempt at a Solution



I can't find any explanation in my lecture notes.
I think that:
molecular mass = mass of one molecule
molar mass = mass of one mole of a molecule

I think they are related by if i took the molecular mass and multiplied it by the number of moles, I would get the molar mass.
Any help explaining these concepts is appreciated!
 
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  • #2
rubenhero said:
molecular mass = mass of one molecule

Correct, but in what units?

molar mass = mass of one mole of a molecule

Correct, but in what units?

I think they are related by if i took the molecular mass and multiplied it by the number of moles, I would get the molar mass.

I guess you mean "number of molecules in a mole", not "number of moles". You are not wrong, but you are still missing one important factor. Again, think about units used for both molar and molecular mass.
 
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  • #3
Is molar mass not the same thing as mass of one mole of the substance in question?
 
  • #4
chikis said:
Is molar mass not the same thing as mass of one mole of the substance in question?

Yes it is.

But without using correct units you will be still off.
 
  • #5
Borek said:
Yes it is.

But without using correct units you will be still off.
If that is the case the unit will be gram per mole i.e gmol-1. How about that?
Is relative molecular mass the same as molecular mass?
 

1. What is the difference between molecular mass and molar mass?

Molecular mass refers to the mass of a single molecule of a substance, while molar mass is the mass of one mole of a substance. Molar mass is calculated by multiplying the atomic mass of each element in a molecule by the number of atoms present and adding them together.

2. How are molecular mass and molar mass related?

Molecular mass and molar mass are related because they both refer to the mass of a substance. However, molecular mass is specific to a single molecule, while molar mass is a more general measurement of the mass of a certain amount of a substance (one mole).

3. Why is molar mass important in chemistry?

Molar mass is important in chemistry because it is used to convert between the mass of a substance and the number of moles present. It is also used in stoichiometry, which involves calculating the quantities of reactants and products in a chemical reaction.

4. How do you calculate molar mass?

Molar mass is calculated by adding the atomic masses of each element in a molecule. The atomic mass can be found on the periodic table. For example, the molar mass of water (H2O) would be calculated as: (2 x 1.008 g/mol) + (1 x 15.999 g/mol) = 18.015 g/mol.

5. Can molar mass be used to determine the formula of a compound?

Yes, molar mass can be used to determine the formula of a compound. This can be done by comparing the molar mass of the compound to the molar mass of known elements and their ratios in the compound. For example, if the molar mass of a compound is 180 g/mol and it is composed of carbon and hydrogen, it can be determined that the formula is C6H6 (180 g/mol = 6 x 12.01 g/mol + 6 x 1.008 g/mol).

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