Warm Up
1-20-16
1. What do we use to measure temperature?
2. What is the difference between heat and
temperature?
3. True or false: Heat is energy and energy is
heat.
Explain your answer.
Agenda
Homework
Turn in HW-specific heat WS
Notes Unit 6-3
Virtual Lab calorimeter
Jan 29- Online HW
Answers:
1. Specific heat
2. O Kelvin
3. Endothermic
4. Exothermic
5. 4.18
6. Delta T
7. O oCelcius
8. 0.416
9. 63,536 Joules
10. 7.974 g
11. 0.2
12. 13,794 joules
13. 0.031
Answers:
14. 27, 912 joules
15. 58,050 joules
16. 12.096 grams
17. 15.01818 Celsius
18. Object B, lower
specific heat means it
requires less heat for
temperature to increase
Unit 6 - 3
Enthalpy
Enthalpy
• Enthalpy – the total quantity of heat in
a reaction
• Changes in enthalpy are measured
through indicators (temperature)
• Represented by ΔH
Enthalpy Change
• The sign of H indicates the direction of
heat transfer.
+H indicates heat is entering the system
(endothermic)
- H indicates heat has left the system
(exothermic).
Enthalpy Change
• For reactions
H = H (products) – H (reactants).
Example:
• 2H2 (g) + O2 (g)  2H2O(g)
H = -483.6kJ
Molar Heat Capacity
• The quantity of heat required to raise
the temperature of one MOLE of a
substance by one degree Celsius or
Kelvin
Molar Heat Calculation
• Q = n x ΔT x Cp
n = moles
Cp = molar heat capacity
Example Problem
• The molar heat capacity of CCl4 is 130.7
J/mol·C. What is the enthalpy change
when 125g of CCl4 is heated from 10 °C
to 32 °C.
Convert to mole if given grams
Calorimeter
• An instrument for measuring the heat of a
reaction during a chemical process
$13,000 – $40,000
Specific Heat Lab
Q gained by water =
Q lost from the metal
Assignments
• Summary
• Virtual calorimeter lab
http://www.wiley.com/college/trefil/047
0118547/vdl/lab_calorimeter/
Homeroom
-AP classes overview
-Reflections and setting goals
-Quote of the week
1-20-16
Homeroom
1-20-16
On a piece of line paper. Answer the
following questions in complete sentences.
1.What were the high point(s) and low
point(s) of last year?
2.List three things your did successfully in
school or outside of school.
3.List several goals you want to achieve this
semester