- #1
meganw
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Homework Statement
A 19.2 g sample of ice at -10.0°C is mixed with 100.0 g of water at 74.9°C. Calculate the final temperature of the mixture assuming no heat loss to the surroundings. The heat capacities of H2O(s) and H2O(l) are 2.08 and 4.18 J g-1 °C-1, respectively, and the enthalpy of fusion for ice is 6.02 kJ/mol.
__________ degrees Celsius
Homework Equations
q = mass * specific heat * (delta) temp
The Attempt at a Solution
I thought I knew how to do it but keep getting it wrong. =(
19.2 g ice at -10.0 deg going to 0 deg:
19.2g x 2.08 J/g deg x 10 deg = 399.96 J
Melting 19.0 g ice at 0 deg requires-
19.2g x (1/18.02 g/mol) x 6.02kJ/mol x 1000 J/kJ x = 6350.77 J
399.96 + 6350.77 = 6750 J
That energy will come from cooling 100.0 g H20:
6750 = (100)(4.18)(T-74.9)
T(final) = 91.04
thats wrong on webassign though...
I also tried doing 74.9 - T to see if that works and I get 58.8 but that's wrong too.
Thanks for any help! =)