elenacondriuc asked:


A chemical engineer studying the properties of fuels placed in 1.500 g of a hydrocarbon in the bomb of a calorimeter, and filled it with O2 gas. The bomb was immersed in 2.500 L of water and the reaction initiated. The water temperature rose from 20.00 C to 23.55 C. If the calotimeter (excluding the water) had a heat capacity of 403 J/K, What is the heat of combustion (qv) per gram of the fuel?

JAE

One Response to “Finding the heat of combustion (qv) per gram of the fuel?”

1. IndygoMorie on January 10th, 2009 2:53 am

   SCOT

   Since the temperature is increases , the combustion of the fuel is must be exothermic so the enthalpy must be negative.

   Increase temperature = 296.55 K – 293 K = 3.55 K

   Heat evolved by reaction
   = heat absorb by the water
   = heat capacity x increase temperature
   = 403 J/K x 3.55 K
   = 1430.65 J

   Thus qv = ^H = - 1430.65 J

   What is the heat of combustion (qv) per gram of the fuel?

   = - 1430.65 J / 1.500 g
   = -953.766 J/g

   Thus the heat combustion is -953.766 J per g of fuel.

Leave a Reply

You must be logged in to post a comment.