Răspuns:
M,C2H6= (2X12gC + 6X1gH)/mol= 30g/mol
-calculez moli at.C din proba
a) niu= N/N,A=3,011x10²³/6,023x10²³mol= 0,5molC
b) m= niuxA,C= 0,5molx12g/mol=6gC
c) 1mol substanta......2molC
X..............................0,5mol
X= 0,25mol substanta
d) 2atC..........6atH
3,011x10²³at-------x= 3,011x3x10²³=> 9,033x10²³at.H
Explicație: