Chemistry
posted by Raven .
What mass of copper solid, initially at 25oC,should be added to 100 g of steam, initially at100oC, if we want exactly half of the steam to
condense?
The specific heat of copper
is 0.385 J g1 oC1.
For water, the heat of
vaporization is 2257 J g−1.

[mass Cu x specific heat Cu x (TfinalTinitial)] + [mass steam x delta Hvap]=0
Substitute the numbers and solve for mass Cu which is the only unknown in the equation.