Mass - Chemistry

Question

What is the mass of exactly 1 mol of the following compounds?

 

N₂O₅ = ? grams

 

Fe(ClO)_{2 = ? grams} 

 

Fe(ClO₃)_{3  =? grams} 

Answer 1

Look up in your chemistry book the atomic weights of all the elements in the compounds, in units of grams/mole.  Add the atomic weights of the elements, remembering to multiply by the number of atoms of each element in the formula.  That gives the molecular weight of the compound in grams/mole, which is the same as the mass in grams of 1 mole of the compound.  I will do the first one for you, and you try the others.

 

N₂O₅ = ? grams

 

Atomic weights:

 

N = 14.01

O = 16.00

 

Molecular weight = 2(N) + 5(O) = 2(14.01) + 5(16.00) = 108.02 grams/mole

 

1 mole of N₂O₅ has a mass of 108.02 grams.