1. The problem statement, all variables and given/known data Is my approach correct? Thanks all :) a)The specific heat capacity of water is 4200Jkg-1K-1 while the specific latent heat of steam is 2.26x106Jkg-1. Explain what is meant by the statement in italics. b) Explain, in terms of molecular motion, the large difference between the two values. c) A polystyrene cup contains 80g of water at 20C. steam at 100C is passed into the water until the final temperature of the water rises to 80C. Determine the mass of steam Which has been passed into water. d) The heat transfer to the cup may be neglected in the calculation. Why? 2. Relevant equations 3. The attempt at a solution a) Specific heat capacity is the heat energy required to raise the temperature of a material weighing 1kg by 1 degree Celsius. The specific latent heat of steam is the heat required to change 1 kg of water to steam without a change in temperature. b) In terms of molecular motion it will require much more heat energy for the kinetic energy of the molecules, to reach a certain point where no force of attraction is present. Therefore this change of state requires more energy, rather than the energy required to heat up the liquid. c) Q=mc∆θ Q=0.080*4200*60 Q=20160J Amount of heat energy given from the steam to the water. Q=ml 20160J=m*2.26x106Jkg-1 m=8.92x10-3kg Mass of steam passed into the water. d) Polystyrene is a poor conductor of heat unlike metal, this material will act as a good insulator thus assuming heat losses are negligible.