-M(miu)= (31gP+3x35,5gCl)/mol= 137,5g/mol
in 137,5g PCl3...........106,5gCl
200g.................m= 200x106,5/137,5 ......calculeaza !!
-n,mol= m/M; n= 200g/137,5g/mol=1,4545mol
1mol.molecule ..contine,,,,,6,023x10²³molecule
1,4545.....................................N= ......calculeaza !!!!