Question

The number of molecules in 4.25 g of ammonia is about

Answer 1

17g of Ammonia makes up one mole of ammonia and it contains avogadro number of molecules.

4.25g of ammonia is 1/4 moles of ammonia and contains 1/4×6.022×10^23 molecules

Answer 2

n/N=m/M where

n=no. of moles

N=avagadros no.

m=given mass

M=molar mass

A.T.Q

N=6.022×10∧23

M=17(NH3)

m=4.25g

n=?

this implies.....n/6.022×10∧23=4.25/17

n=4.25/17×6.022×10∧23

n=1.5055×10^23

hope its correct