How do you calculate the number of moles in 50.0g AgNO3
First, you must calculate the molar mass of the molecule AgNO3. This is done by looking at the value on the periodic table for each individual element in the molecule.
According to the molecular formula AgNO3, you have 1 Ag, 1 N and 3 O’s.
Therefore the total molar mass, M = M(Ag) + M(N) + 3M(O) = 107.8682 g/mol + 14.0067 g/mol + (315.9994 g/mol).
**We multiply the molar mass of O by 3 because the formula has the subscript “3” after the O.
The total molar mass is then M = 169.8731 g/mol.
From here, using the formula n = m/M and that we are given the mass of AgNO3 and that we’ve found it’s molar mass, we can find the number of moles in this sample.
n = (50.0 g)/(169.8731 g/mol) = 0.294 moles.
** The answer is rounded to three significant figures, as the mass of the sample limits our accuracy.