Question

how many moles of NH3 will be there in 76.5 gram of NH3

Answer 1

answer is 76.5 mole because 1mole of NH3 =1g of NH3.

Answer 2

we know that,
Atomic mass of Nitrogen= 14u
Atomic mass of Hydrogen =1u
So,
To find out the moles of NH3 first we have to find out the gram molecular mass.

So,
gram molecular mass= 14×1 + 1×3
=14+3
=17gram
Now,
Number of moles of molecules= Mass of substance/ gram molecular mass
=76.5/17
=4.5
So, 4.5 moles is the answer