masa unui mol Ca contine numarul lui Avogaro de atomi, adica
40g......................6,023x10²³ at Ca
x.....................................10 at
x= 56,4x10⁻23 g
1mol H2SO4 are masa (2x1gH+32gS + 4x16gO)
4mol.....................................................x.......................................calculeaza !!!!!