Eu cred ca se cere sa se verifice afirmatiile a,b,c,
r1:C+1/2O2----->CO ori a moli
r2;C+O2------> CO2 ori 2a moli
total moli O2= a/2+2a=2,5a
2,5a=10---> a=4 mol
a_r1: intra 4mol C; m=n(niu)xM(miu)=> 4molx12g/mol= 48g C ADEVARAT
b) r2: rezulta :2a=8mol CO2 FALS
c) total moli amestec: a,CO+2a,CO2= 3a= 12mol
in 12 mol amestec........sunt 4mol Co
100mol............................x------------------------calculeaza si verifica !!