How many grams of oxygen are in 7.75 moles of dinitrogen trioxide?

Question

Help me please 

Answer 1

Hi Roxana

 

dinitrogen trioxide is N₂O₃

 

First lets determine the molar mass of the molecule

 

N has an atomic mass of 14.0067

O has an atomic mass of 15.9994

 

We need the grams of oxygen so the molar mass of oxygen in this molecule is

3(15.9994) = 47.9982 g/mol

 

And the molar mass of the N₂O₃ molecule is

 

2(14.0067) + 3(15.9994) = 76.0116 g/mol

 

So Oxygen is 

47.9982/76.0116 = 0.6315 or 63.15% of the total

 

With 7.75 moles, 

 

7.75 mol • 76.0116 g/mol = 589.09 grams of N₂O₃

But since Oxygen is 63.15% of the total weight,

589.09 • .6315 = 372

 

There are 372 grams of oxygen in 7.75 moles of N₂O₃