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Please help physics problems on phase change?

  1. Mar 15, 2010 #1
    1. The problem statement, all variables and given/known data

    1. What amount of energy is released whan 10g of steam at 100 degrees C condenses and then cools to water at 0 degrees C?

    2. 1840 calories of heat is added to a 300g block of ice at 0 degrees C. what amount of ice melts?

    3. 3600 calories of heat is removed from 5g of steam initially at 100 degrees C. In what form is the water in the end?

    4. Consider 35g of water at 1000C. If 4g rapdily evaporates, what will be the temperature of the remaining 31 grams of water?

    2. Relevant equations

    Q = mcT

    3. The attempt at a solution

    1. it takes 540 then 100 then 80...do i add those up and multiply by 10?
    2. no idea
    3. no idea
    4. i know evaporation is a cooling process so there will be less heat in the 31 grams of water...but nothing else
  2. jcsd
  3. Mar 15, 2010 #2
    Use the relation between heat capacity, mass, temperature and heat.
    Look up values for heat capacity, specific heat capacity and latent heat of fusion/melting for water.
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