Question

The number of atoms in 4.25 grams of NH₃ is approximately(need the answer with a detailed explanation)

Answer 1

1 mole of Ammonia is 17gm. {NH3= N(14gm)+ H(1gm)+H(1gm)+H(1gm)}

Now 1 mole of any substance at STP always has Avogadro's number of molecules i.e. 6.023*10^23.

So 1 mole or 17gm of Ammonia will have 6.023*23 molecules of NH3.

Here it's 4.25gm or 4.25/17= 0.25moles of Ammonia.

Therefore 0.25 moles of Ammonia will have 0.25*6.023*10^23 molecules.

As 1 molecule has 4 atoms. (1 of Nitrogen and 3 hydrogen),

We will have 4* 0.25* 6.023*10^23 atoms in 0.25 moles of Ammonia.

Answer is 4.25gms will have 6.023*10^23 number of atoms in it.

Hope you get it.