How would you find molar mass?
1 Answer
Add up the atomic mass of all the atoms in the molecule
Explanation:
Find a periodic table and look at the atomic mass of each atom in the molecule.
I prefer to use tables with whole number atomic masses, but that is just personal preference.
Then simply find out how many of each atom is in the molecule and add the respective atomic masses to find the molecular or molar mass.
For example water
Water has a molar mass of 18
Sulfuric acid
Sulfuric acid has a molar mass of 98.
The molar masses will be slightly different if you are using a table with more accurate decimal values for atomic mass. Ask your teacher or tutor if you are not sure which one to use.
Another way to find molar mass if amount and mass of a substance are known is by using the formula
Where
For example if you had 7 moles of sulfuric acid and it had a mass of 686 grams:
The equation can also be rearranged to give some other useful equations:
and