Respuesta :
Best Answer: Sorry its kind of hard to explain, you just need to study hesslaw, practice makes perfect, keep studying!
A. REACTION 2 IS MULTIPLIED BY 3 (HESS LAW)
ΔH2= -6129 j
B. IF REACTION IS REVERSED YOU FLIP THE SIGN OF ΔH
ΔH = 92.3 kJ
C. KIND OF HARD TO EXPLAIN, BUT I CAN TRY AND SHOW YOU
EQUATION 1 (FLIP) CH4 --> C + H2
EQUATION 4 (FLIP AND MULTIPLY BY 2) H2O(g) --> H2O(l)
ΔH = -890.7
A. REACTION 2 IS MULTIPLIED BY 3 (HESS LAW)
ΔH2= -6129 j
B. IF REACTION IS REVERSED YOU FLIP THE SIGN OF ΔH
ΔH = 92.3 kJ
C. KIND OF HARD TO EXPLAIN, BUT I CAN TRY AND SHOW YOU
EQUATION 1 (FLIP) CH4 --> C + H2
EQUATION 4 (FLIP AND MULTIPLY BY 2) H2O(g) --> H2O(l)
ΔH = -890.7
[3 mol CO2(g) + 4 mol H2O(g)] - [1 mol C3H8(g) + 5 mol O2(g)]
[3 · (213.74 J/mol·K) + 4 · (188.825 J/mol·K)] - [1 · (269.9 J/mol·K) + 5 · (205.138 J/mol·K)]
=100.93 J/mol·K
Answer: 100.93 J/mol·K