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Q=MCdelta T w/phase change, cant get a logical answer
**Found my Error, Ignore**
I need to figure this out before i get tested on something similar cup of 200 ml water at 95C. Put 40g dry ice(molar mass=44g/mol) initially at negative 78C, with enthalpy of sublimation of 8.76kJ/mol. Assume final temp of CO2 gas and water are equal. what is final temp? specific heat of water 4.186j/gC "" of C02 gas .85 j/gC How i went about doing it, 40gCO2/46mol * 8.76kj/mol= 7617 j to sublime dry ice. I took 7617j and Q=mcdeltaT to find the water drops 9.01C to sublime ice, then i took the new water temp and used it in the MCdeltaT=MCdeltaT style. (200)(4.186)(T-85.99)=(40)(.850)(T- -78) And i end up with a number that says the water is getting warmer, BLEEEEH. Please help i need to figure how to do a problem like this before a test. |
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