Question

How many grams of steam at 100 degrees celcuis would be required to raise the temperature of 35.8 g solid benzene (C6H6) from 5.5 - 45.0 degrees celcius.

(the melting point of benzene is 5.5 degrees celcius, delta H fusion for benzene is 9.87 kj/mol, specific heat for benzen is 1.63 J/gdegC and delta H vap. for steam at 100 degrees C is 40.7 kj/mol

Answer 1

q1 = heat to melt benzene.
q1 = mass benzene x heat fusion.

q2 = heat to move benzene from 5.5 to 45 C. Note the correct spelling of celsius.
q2 = mass benzene x specific heat benzene x (Tfinal-Tinitial).

q3 = heat lost by steam to condense to liquid water.
q3 = mass steam x heat vaporization. (This is the unknown).

q4 = heat lost by liquid water at 100 going to 45.
q4 = mass water x specific heat water x (Tfinal-Tinitial).
Total Q = q1 + q2 + q3 + q4.
Watch the signs and watch the units.
Adding heat is +. Heat lost is -.

Answer 2

How do i find the mass of water?

Answer 3

mass of water is the same as the mass of the steam (after it condenses). Just call mass steam X and mass water as X.