Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
6 Cards in this Set
- Front
- Back
|
What is Energy?
|
1. The ability to do work
2. Conserved 3. Made of heat and work 4. A state function 5. Independent of the path, or how you get from point A to B 6. Work is a force acting over a distance 7. heat is energy transferred between objects because of temperature difference. |
|
|
Describe "The Universe"
|
1. Divided into tow halves: the system and the suroundings
2. System: part you are concerned with 3. Surroundings: the rest 4. Exothermic reactions realease energy to t the surroudings and endothermic reactions absorb energy from the surroundings |
|
|
What are the common Units of Heat?
|
1. The Calorie (cal): the quantity of heat required to change the temp of one g of water by 1 degree C
2. The Joule (J) is the SI unit for heat 3. 1 cal =4.184 J (also specific heat capacity for water) |
|
|
Positive or Negative heat flow?
|
1.Every energy measurement has three parts: a unit (joules or cal) a number, and a sign
2. NEGATIVE = EXOTHERMIC 3.POSITIVE = ENDOTHERMIC 4. take the systems point of view to decide signs 5. q is negative when the system loses heat enery and poisive when the system absorbs energy |
|
|
What does the First Law of Thermodynamics Entail?
|
1. The energy of the universe is constant
2. Aka law of conservation of energy 3. q = heat |
|
|
Describe Enthalpy
|
1. Heat content of a substacne
2. Depends on many things 3. Symbol is "H" 4. Can't be directly measured 5. Changes in enthalpy can be calculated: change in H = Hfinal - H initial 6. Changes in q can be used to find change in enthalpy |
