1. r1: 2C+3H2---> C2H6..........................Δ..H,f=?
r2: C+O2----> CO2..............................ΔH,f=-393,5kj/mol
r3: H2+1/2O2--> H2O.........................Δ.H,f= -285,5kj/mol
r1= 2 r2+3 r3...........................ΔHf= 2molx(-393,5kj/mol)+3molx(-285,5kj/mol
calculeaza !!!!!
2.ro=0,79g/ml=m/v, v= 1dmcub=1 l=1000ml---> m= 79og
M, alcooletilic= 46g/mol
n=m/M;n= 790g/46g/mol
1mol............................................ΔH (trebuie sa-l cunosti in kj/mol)
790/46mol...........................................x