# chemistry

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How much heat would be released by the condensation of 5.40 g of steam at 100 °C and the subsequent cooling of the water to 25 °C? [ÄHvap = 40.7 kJ/mol at 100 °C; Cp for H2O(l) is
4.18 J g-1 °C-1]

• chemistry -

Heat is released by condensation steam at 100 C to water at 100 C.
q1 = mass x Hvap.

q2 = heat is released by cooling water from 100 C to 25 C.
q2 = mass x specific heat x (Tf - Ti)
where Tf is final T and Ti is initial T.
Both q1 and q2 are negative numbers.
Total heat released is q1+q2.

• chemistry -

i did what u wrote above. but did not have the answer right. The answer from the book is 13.9 kJ

• chemistry -

Check your working. Note that dHvap is per MOLE and the answer q1 will be in

kJ

whereas the answer for q2 will be in

J

• chemistry -

why are there two q1 and q2?

• chemistry -

wait nvm,

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