How many nitrogen atoms are present in a molecule of vitamin B12 if its percentage composition is 14.47% and
vitamin B12 has a molecular weight of 1355 amu?

Question

How many nitrogen atoms are present in a molecule of vitamin B12 if its percentage composition is 14.47% and 
vitamin B12 has a molecular weight of 1355 amu?

aaronq · Answer

how much mass is nitrogen?

elleblythe · Answer

you mean atomic weight? 14.01 @aaronq

elleblythe · Answer

is it correct if i just multiply 0.1447(1355) which will give the mass of nitrogen in vitamin b12, then i will use stoichiometry to convert the value that i got to atoms, so it will become the answer multipled by (avogadro's number/1mole)?? @aaronq

elleblythe · Answer

how would i do that? could i multiply the amu with 1.661x10^-24 to change it to grams?

aaronq · Answer

so find the mass of N in B12, then just divide it by the molar mass of nitrogen.

aaronq · Answer

nevermind what i said earlier