Lab 4 of 2LB
Lab 7 of 40B
Specific Heat and Latent Heat

Data Tables

The specific heat of water is c _water = 1.00 cal/g ^oC

1. Water equivalent of the Calorimeter

m(beaker)
m(beaker + water)
mwater
T1, (cool calorimeter)
T2, (hot water in beaker)
back-up T f, ( T 120 second)
cut-off T f ( y-intercept from the corrected Graph "Temperature versus time")




• Plot the graph of "Temperature versus time" on screen.

• Write down the temperature at time = 120 second, as T_{120 second}, as a back-up T _f.

• (1.0 point) Question: How is the slope of your graph related to the heat loss of the calorimeter?

• Delete all points before time = 120 second.

• (0.5 point) Print out the corrected Graph of "Temperature versus time."

• (0.5 point) Fill out the last row with B, y-intercept, on that graph, which is your cut-off T_f.

• (0.5 point) Plug values in : m _water c _water (T₂ - T _f) = C _calorimeter (T _f - T₁)

• (0.5 point) Calculate the heat capacity of the calorimeter, C _calorimeter = ____________, Unit:(cal/ ^oC)

2. Latent Heat of Fusion of ICE

m calorimeter
m(calorimeter + water)
m(calorimeter + water +ice)
new m water
mice
T 1 (the initial temperature)
T f (the final temperature)



QUESTION: (3.0 POINTS)

• (0.5 point) Print out the second Graph of "Temperature versus time."

• (1.0 POINT) Locate your T ₁ and T _f from your Graph of "Temperature versus time."

• (0.5 point) Calculate the Latent Heat of fusion of ice, L, from:

  C _calorimeter (T ₁ - T _f) + m _water c _water (T₁ - T _f) = m_ice L + m_ice c _water (T _f - 0℃)

  Latent heat, L = ____________, Unit:(    )

• (1.0 POINT) Compare your measurement with the standard value of 79.7 cal/g

  Requirement:

  (0.5 point) What is the percent error between your experimental calculation and the empirical measurement, 79.7 cal/g ?

  (0.5 point) Write down one of the possible sources of the systematic error with a logical reason and a numerical estimation. Any simple answer implying "Human Error" or "Stupidity" is totally unaccpetable!