Some very hot rocks have a temperature of #370 ^o C# and a specific heat of #270 J/(Kg*K)#. The rocks are bathed in #108 L# of boiling water. If the heat of the rocks completely vaporizes the water, what is the minimum combined mass of the rocks?

1 Answer
May 18, 2017

The mass of the rocks is #=3343.7kg#

Explanation:

The heat transferred from the rocks to the water, is equal to the heat used to evaporate the water.

For the rocks #DeltaT_o=370-100=270º#

Heat of vaporisation of water

#H_w=2257kJkg^-1#

The specific heatof the rocks is

#C_o=0.27kJkg^-1K^-1#

The mass of water is #m_w=14kg#

# m_o C_o (DeltaT_o) = m_w H_w #

#m_o*0.27*270=108*2257#

The mass of the rocks is

#m_o=(108*2257)/(0.27*270)#

#=3343.7kg#