# Find the resulting sample given specific heat of ice, water vapor, and vaporization

Submitted by alanavo on Sat, 12/14/2013 - 00:54

Assume 10,000 J of energy is added to 2.0 moles (36 grams) fo H2O as an ice sample at -10°C. The specific heat of liquid water is 75.2 J/mol·K; the molar heat of vaporization is 40.6 kJ/mol. The specific heat of water vapo is 30.6 J/mol·K. The resulting sample contains which of the following?

a) only ice

b) ice and water

c) only water

d) water and water vapor

e) only water vapor

Assume 10,000 J of energy is added to 2.0 moles (36 grams) fo H2O as an ice sample at -10°C. The specific heat of liquid water is 75.2 J/mol·K; the molar heat of vaporization is 40.6 kJ/mol. The specific heat of water vapor is 30.6 J/mol·K. The resulting sample contains which of the following?

Assuming that sp. heat of ice is roughly equivalent to the sp. heat of steam, it will require

heat to raise temp of ice to m.pt =  2mol  x  31 J/mol K    x  10K  = 620 J

heat to melt ice =  2 mol   x  40,600 J/mol  =   81,200 J

heat used to heat liq.  to b.pt  =  2 mol   x  100K  x  75.2 J/mol K   =    15,400 J

heat remaining to vaporize water  =  10,000 -  620 J   -  81,200 J  -   15,400 J

Since not all of the heat require to completely vaporize the water is available, the sample will consist of  mixture of liquid water and steam at 100C.