Răspuns:
MgCl2 clorura de magneziu (2 ion Cl-)
M.MgCl2 = 24+2×35,5=95 g/mol
la 1 mol MgCl2.....95g
95g.......... ..2x6,022x10²³ ioni Cl-
28,5g ............................. n ioni Cl-
n=28,5×2×6,022×10²³/95== 3,613x10l²³ ioni Cl-
succes pe mai departe!