Question

Sa se determine numarul de molecule numarul total de atomi din 500g hidroxid de aluminiu

Answer 1

calculez moli Al(OH)3 si, apoi, molii de atomi ce compun aceasta molecula:
M= (27gAl+3gH+48gO)/mol=78g/mol Al(OH)3
n sau niu= 500g/78g/mol=6,41mol Al(OH)3

in 6,41mol Al(OH)3   sunt,,,,,6,41molxN,A molecule/mol   Al(OH)3
                                             6,41mol Al---> N,Al= 6,41xN,Aatomi
                                             3x6,41molH--> N,H=3x6,41xN,A   atomi H
                                             3X6,41molO-->N,O= 3x6,41xN,A atomiO

N,molecule--> vezi 6,41xN,A
N,atomi,total-->(6,41+3x6,41+3x6,41)N,A    unde N,A=6.023X10²³