October 2, 2013

Today: Students finished Lab P38 and worked on the graph and summary.  The lab is due tomorrow.

P38 Questions

1. Graph your calorie loss of hot water (x-axis) vs calorie gain of cold water (y-axis).  Each trial gives you the coordinate pairs (Hot Loss, Cold Gain) Then draw a BEST FIT LINE to show the average of your data.

   a. What are the relationships, if any, between the heat gained by cold water and the heat lost by the hot water.
  b. What is your hypotheisis to explain the heat exchange between hot and cold water?

2. Compare your predictions with the data on heat ganied and heat lost when cold water and hot water are mixed.

a. were your predictions accurate?
b. How might you predict the temperature of mixtures of hot and cold water?

3. If your investigation had been done under IDEAL conditions, not instrument errors or human errors would have affected the measurements of heat gained or lost by each sample.

a. Under ideal conditions, what temperature of water would you predict for a mixture of 50g of water @ 80 degrees mixed with 20g of water @ 25 degrees?

BONUS: From that answer can you predict the calories lost by the hot water?  Gained by the cold?

b. What is your hypothesis to explain the heat exchange between hot and cold water mixed in a calorimeter?

No comments:

Post a Comment