Posted by Please Help! on Monday, November 8, 2010 at 11:57pm.
If 1.10 g of steam at 100.0 degrees celsius condenses into 38.5 g of water, initially at 27.0 degrees celsius, in an insulated container, what is the final temperature of the entire water sample? Assume no loss of heat into the surroundings

Chemistry  DrBob222, Tuesday, November 9, 2010 at 12:34am
heat lost by 100 C water + heat gained by cold water  heat lost by condensation =0
1.1*4.184*(Tf100) +[38.5*4.184*(Tf27)]  1.1*2257 = 0
Solve for Tf.
You can do it another way if you wish.
First calculate how much the condensing steam will raise the T of cold water.
1.1*2257 = 2482.7 J released.
38.5*4.184*(Tf27) = 2482.7
Tf = 42.41 THEN
heat lost by 1.1g steam @ 100C + heat gained by 41.41 C water = 0 and recalculate Tf EXCEPT, of course, Tinitial is 42.41 and not 27.0 C. Same answer is obtained. 
Chemistry  Please Help!, Tuesday, November 9, 2010 at 9:14pm
Thank you! what is the 2257 from?

Chemistry  Chandler, Tuesday, November 4, 2014 at 12:07pm
2257 is the heat of vaporization of water.