Chemical Thermodynamics Question 161
Question: If $ C+O_2\to CO_2+94.2,kcal $
$ H_2+\frac{1}{2}O_2\to H_2O+68.3,kcal $
$ CH_4+2O_2\to CO_2+2H_2O+210.8,kcal $ then the possible heat of methane will be [MP PET 1990]
Options:
A) 47.3 kcal
B) 20.0 kcal
C) 45.9 kcal
D) - 47.3 kcal
Show Answer
Answer:
Correct Answer: B
Solution:
$ C+{O_{2,}}\to CO_2+94.2Kcal. $ -..(i) $ H_2+\frac{1}{2}O_2\to ,H_2O+68.3Kcal. $ -.(ii) On multiplication of eq. (ii) by 2 and than adding in eq. (i) $ C+2H_2+2O_2\to CO_2+2H_2O+230.8Kcal $ -(iii) On subtracting eq. (iii) by following eq. $ CH_4+2O_2\to CO_2+2H_2O+210.8Kcal. $ we get, $ C+2H_2\to CH_4\Delta H=20Kcal. $
