Download presentation
Presentation is loading. Please wait.
Published byClare Carson Modified over 9 years ago
1
Ch 5: Thermochemistry The relationship between chemical reactions and energy changes involving heat is called thermochemistry.
2
Types of Energy Potential energy: energy objects posses as a result to position to other objects Kinetic energy: energy posses by virtue of motion (E=1/2mv 2 )
3
Units of Energy Joule = 1kg-m 2 /s 2 1 calorie = 4.184 J 1 Cal = 1000 cal = 1 kcal
4
System: the focus of study Surroundings: everything else
5
Energy used to cause an object to move against a force is called work. W = F x d
6
Heat is the energy transferred from a hotter object to a colder one.(q) Energy is the capacity to do work or transfer heat.(E)
7
First law of thermodynamics Energy is conserved. E = E final - E initial
8
E = q + w Anytime work or heat acts on the system it is a positive value. (Vice-versa)
9
When a process occurs in which the system absorbs heat, it is called endothermic. A process in which the system evolves heat is called exothermic.
10
Calculate E The system absorbs 77.5 kJ of heat while doing 63.5 kJ of work on the surroundings.
11
E = 14 kJ Endothermic
12
How to solve for q q = mc t c = the specific heat of the material. H 2 O = 4.18 J/gK
13
If a 3.0 g metal is heated to 95 o C and added to a cup of water (50g) at 23 o C, and the water raises to 30 o C, what is the specific heat of the metal?
14
If 125 mL of water at 88 o C is added to 50 mL of water at 30 o C, what is the new temperature of the water?
Similar presentations
© 2024 SlidePlayer.com. Inc.
All rights reserved.