Percentage of nitrogen in urea

[chawki]

Homework Statement

Calculate the percentage of nitrogen in urea (H2NCONH2).

Homework Equations

The Attempt at a Solution

I tried and found %N = 46.66%

 

[DDTea]

That's the answer I get too. % N = [(molar mass N)(# N atoms in molecule)]/(molar mass of molecule)

 

[chawki]

i got it by this law: 28/N% = 60/100%
therefore: N% = (28 X 100) / (60)

 

[DDTea]

Equally valid. If you rearrange your equation (or mine), you'll see that they are equivalent.

I like to show units, though, because it offers a good "check" if I need it and can keeps me from getting confused.