NEET2016ChemistryThermodynamics (C)Actual
The heat liberated when 1.89 ~g of benzoic acid is burnt in a bomb calorimeter at 25^ C and it increases the temperature of 18.94 ~kg of water by 0.632^ C . If the specific heat of water at 25^ C is 0.998 cal / g - deg , the value of the heat of combustion of benzoic acid is
Options
- A881.1 kcal
- B771.12 kcal
- C981.1 kcal
- D871.2 kcal
Correct answer
B. 771.12 kcal
Step-by-step solution
Given : Weight of benzoic acid =1.89 ~g ; Temperature of bomb calorimeter =25^ C =298 ~K ; Mass of water (m)=18.94 ~kg =18940 ~g ; Increase in temperature ( t)=0.632^ C and specific heat of water (s)=0.998 cal / g -deg. We know that heat gained by water or heat liberated by benzoic acid (Q)=m s t= 11946.14 122 1.89 =771126.5 cal =771.12 kcal