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Topic: Enthalpy Change Problem  (Read 1589 times)

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Offline Parkerhaze

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Enthalpy Change Problem
« on: December 03, 2018, 12:33:40 PM »
Exactly 18.0  mL of water at 30.0 °C is added to a hot iron skillet. All of the water is converted to steam at 100.0°C. The mass of the skillet is 1.25  kg. What is the change in temperature of the skillet?

I feel like more information is needed. I've looked up the molar and specific heat capacity of iron and every answer I've given has been wrong.I am on attempt 33. Can someone please assist me?

Offline chenbeier

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Re: Enthalpy Change Problem
« Reply #1 on: December 03, 2018, 01:13:57 PM »
Q(iron) lost = Q(water obtain)
m(iron) * c(iron) * (T(iron- T(mix)) = mWater * cWater * (Tmix - T(water))
m iron =1250 g
m water 18 g
T iron =?
T mix `= 100° C
T water = 30° C
c heat capacity of water and iron

Offline Parkerhaze

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Re: Enthalpy Change Problem
« Reply #2 on: December 03, 2018, 03:15:29 PM »
I already did that and got the wrong answer

Offline Borek

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Re: Enthalpy Change Problem
« Reply #3 on: December 03, 2018, 04:21:02 PM »
Show the numbers and details of your approach, hard to say what went wrong not seeing it.
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Offline mjc123

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Re: Enthalpy Change Problem
« Reply #4 on: December 04, 2018, 04:50:56 AM »
It is not said that the iron and water reach an equal temperature. The water evaporates at 100°C; the skillet may still be hotter. The question asks for the change in temperature of the iron.
And in addition to mcΔT, you need to account for the enthalpy of evaporation of the water.

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