chemistry
posted by jules .
given the following info for water specific heat capacity of steam 2.03 j/g degrees calculate the total quanity of heat evolved when 10.0g of steam is condensed,cooled,and frozen to ice at 50 degrees

This is best done in stages. There are just two formulas involved. Remember them.
q1 = heat released on the phase change from vapor (steam) at 100 C to liquid water at 100 C.
q1 = mass steam x heat vaporization. (formula 1)
q2 = heat released on cooling liquid water at 100 C to liquid water at zero C.
q2 = mass water x specific heat water x (TfinalTinitial)[formula 2not a phase change but moving WITHIN a phase, in this case all liquid].
q3 = heat released on the phase change of liquid water at zero C to solid ice at zero C.
q3 = mass water x heat fusion (formula 1 again except we are freezing it and not condensing it).
q4 = heat released on cooling ice from zero C to 50C. (moving within a phase again)
q4 = mass ice x specific heat ice x (TfinalTinitial) (formula 2 again.)
Total q = sum of individual qs. 
A 3.0−L sample of a 6.2M NaCl solution is diluted to 75L .