1. EQ: Describe the parts and each part’s function in a calorimeter?
Calorimetry
EQ: Describe the parts and each part’s function in a calorimeter?

2. A. Calorimeter 1. Calorimeters measure Heat change 2. Parts
(used to measure ΔT)
(for minimal heat transfer from/to outside)
(with known mass)
C(water) = J/g°C

3. A. Calorimeter 3. Universe = system + surroundings
System: Part of universe you are interested in
Surroundings: Everything outside the system

4. A. Calorimeter
4. Calorimetry depends of the Law of conservation of energy
Heat lost or gained by the reaction or metal = Heat lost or gained by the calorimeter (water)
5. Heat absorbed= +q
Heat released = -q

5. B. Calorimeter Calculations
q = mcΔT
1. Type 1: calculating energy change of a rxn
Ex: 25.0 g of water containing mol HCl is added to 25.0 g of water containing mol NaOH in a foam cup calorimeter. Ti = 25oC & Tf = 32.0oC. Calculate the heat released during this reaction
Given:
q = ?
m = 25.0 g g = 50.0 g
c = J/g °C
ΔT = = 7oC
Work:
q = mcΔT
q =(50.0g)(4.184J/goC)(7oC)
= J
=1000 J
qcal = -qrxn
=-1000 J

6. B. Calorimeter Calculations
2. Type 2: solving for c when q is known
Ex: Calculate the specific heat of a 45 g substance that produces 2,000 Joules of heat and changes in temperature by 70°C.
Given:
q = 2,000 J
m = 45 g
c = ?
ΔT = 70°C
Work:
q=mcT
c=q/mT
c=2,000 J/(45g x 70°C)
c= 0.6 J/g°C

7. B. Calorimeter Calculations
3. Type 3: solving for c when q is unknown
Ex: A 50.0 g piece of metal is heated to 115.0°C and is placed into a calorimeter with 125 g of water whose initial temperature was 25.6°C. Both the water and the metal have a final temperature of 29.3°C. What is the specific heat of the metal?

8. B. Calorimeter Calculations
Given:
Water
q = ?
mH2O = 125 g
c = J/g°C
Ti = 25.6°C
Tf = 29.3°C
ΔT = 29.3°C – 25.6°C
= 3.7°C
Metal
q = ?
mmetal = 50.0 g
c =?
Ti = 115°C
Tf = 29.3°C
ΔT = 29.3°C – 115.0°C
= -85.7°C

9. B. Calorimeter Calculations
Work:
Step 1: Calculate the heat gained by water
qcalorimeter=(125 g)(4.184 J/g°C)(3.7°C)
= 1935 J =1900 J
Step 2: Heat gained = Heat lost
qsample = - qcalorimeter (change the sign of q)
= J

10. B. Calorimeter calculations
Step 3: Determine Specific heat for metal
q = mcΔT
c = q
= J
= 0.44 J/g°C
mΔT
(50.0g · -85.7°C)