SE utilizeaza relatiile : n= m/M, n= V/Vo, n= N/N,Avogadro
a) m/M= N/N,A 7000g/28g/mol= N/N,A-->
N=250molx6,o23x10²³molec/mol
b)V/Vo= N/N,A 7000L/22,4l/mol=N/N,A-->
N=312,5molx6,023x10²³molec/mol
c) pV= nRT 3xV= 312,5x0,082x(273+27)----.V=2562,5 l
2562,5/22,4= N/N,A---> N= 114,4molx6,023x10²³molec/mol