Question

Prin oxidarea totala a 79,6 g de cauciuc CAROM 1500 s-au obținut 134,4 L (c.n) de CO2. Raportul molar al monomerilor in cauciuc este:
A) 2:3
B) 3:2
C) 1:1
D) 2:1
E) 1:2

Answer 1

cauciuc :   [-(-CH2-CH=CH-CH2-)x(-CH3)C(C6H5)-CH2-)y]n
C(4x +9y)H(6x+10y)  + O2 ⇒ (4x+9y)CO2 + (3x+5y)H2O
M = 54x + 118y
n monomer = 79,6/[2(27x+59y)] = 39,8/(27x+59y)
nCO2 = 134,4/22,4 = 6 moli = (4x+9y)·n monomer
39,8·(4x+9y)/(27x+59y) = 6
79,6x + 179,1y = 81x + 177y
2,1y = 1,4x     y/x = 2/3 (α metilstiren/butadiena)