Răspuns:
M,Ca(OH)2=74g/mol
niu= m/M= 148/74mol=2mol
1mol...............6,023x10²³molec (numarul lui Avogadro)
2mol...............x
x= 12,046x10²³ molec
1mol molec.....................2mol atomiH
2mol...................................x= 4mol atomi H
1mol atomi...........6,023x10²³atomi
4mol.........................x= 24,092x10²³atomiH.
Explicație:
