The amount of energy released by burning a fuel source, measured in energy per mass, is called the fuel value. If all of the energy obtained from burning 1.21 lb of ethane (fuel value is 11.36 kcal / g) is used to heat 121.5 kg of water at an initial temperature of 20.0 ∘ C, what is the final temperature?

Energy from burning Ethane = 1.21 lb

Converting the lb to g

1 lb = 453.59g

Then, the mass of Ethane in gram is

1.21*453.59=548.844g

Fuel heat energy = Mass of ethane * fuel value

Fuel energy = 453.59*11.36

Fuel energy = 6234.87Kcal

Note=1kcal=1°C/kg

Fuel energy = 6234.87°C/kg

Then,

∆T = energy / mass heated

∆T=6234.87 / 121.5kg

∆T=51.32°C

Then, the final temperature Is given as

Tfinal = Tinitial + ∆T

Tfinal = 20+51.32

Tfinal=71.32°C