Phase Change Problems: How to Solve for Heat Release and Temperature Changes

AI Thread Summary
To solve phase change problems involving heat release and temperature changes, it's essential to apply the appropriate equations. For Q1, calculate the heat released by freezing steam into ice using the formula for heat change, incorporating specific heat and latent heat values. Q2 involves condensing steam and cooling water, where the same approach applies, focusing on temperature changes. Q3 requires determining the final temperature of tea after adding ice, treating both as water. Understanding these concepts and equations will help in preparing for the test.
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Homework Statement



I have three questions I need help on. Can someone please explain to me how to do them, how to correctly set up the problem, and what I need to know. I have a test tomorrow. Thanks!

Q1: How much heat is released freezing 75 grams of steam at 110 degrees C into ice at -5.1 degrees C

Q2: How much heat is released in condensing 43 grams of steam at 100 degrees C and then cooling the water to 20 degrees C.

Q3: I make a cup of tea with 43 g of water at 99 degrees C. To cool it, I add 5.1g of ice at 0 degrees C. By how much will the temperature of the tea come down by once I add the ice? (Treat tea the same as regular water)



Homework Equations



Change in Heat= mass*specific heat*change in temperature
Change in Heat=mass*latent heat




The Attempt at a Solution

 
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Q1 is straight forward. Just use the first equation you posted.

\Delta Heat = m (Cp) ( \Delta Temp)

Cp is specific to the material and you can look it up for homework and will most likely be provided for tests.

Q2 is the same as Q1. Let me know if you don't understand the first two. It should just be plugging in numbers for each variable with change in temperature equal to final temp minus the starting temp.

Q3 I don't remember.
 
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