Question

calculeaza masa de apa ce contine 7,77 x 10^16 atomi de hidrogen

Answer 1

-calculez numarul de moli H, folosind numarul lu iAVOGADRO
n(niu)=N/ N,A  
niu= 7,77x10¹⁶atomi/ 6,023x10²³ atomi/mol=1,29x10⁻⁷mol H
- calculez moli H2O care contine acest numar de mol H
1mol H2O........2mol H
X..................1,29x10⁻⁷mol
X=1,29X10⁻⁷/2= 0,645X10⁻⁷ mol H2O
-calculez masa de apa
m= niu x miu
m= 0,645x10⁻⁷molx 18g/mol=........................calculeaza!