kg water into steam at ° C. So, steam at ° C carries . × J kg – more heat than water at ° C. This is why burns from steam are usually more serious than those from boiling water.
Example . When . kg of ice at ° C is mixed with . kg of water at ° C in a container, the resulting temperature is .
° C. Calculate the heat of fusion of ice. ( s water = J kg – K – ) Answer Heat lost by water = ms w ( θ f – θ i ) w = ( . kg) ( J kg – K – ) ( .
° C – . ° C) = 54376. J Heat required to melt ice = m L f = ( . kg) L f Heat required to raise temperature of ice water to final temperature = m I s w ( θ f – θ i ) I = ( .
kg) ( J kg – K – ) ( . ° C – ° C) = . J Heat lost = heat gained 54376. J = ( .
kg) L f + . J L f = . × J kg – . Table .
Temperatures of the change of state and latent heats for various substances at atm pressure Substance Melting L f Boiling L v Point ( ° C) ( J kg – ) Point ( ° C) ( J kg – ) Ethanol – . . Gold . .
Nitrogen – . – . Oxygen – . – .
Water . . Example . Calculate the heat required to convert kg of ice at – ° C kept in a calorimeter to steam at ° C at atmospheric pressure.
Given specific heat capacity of ice = J kg – K – , specific heat capacity of water = J kg – K