Exam 2 Lecture 1 Thermodynamics

Question 1

define energy (chemical reactions)

Answer 1

Capacity to do work or supply heat

Question 2

Chemical THermodynamics

Answer 2

The study of energy and it’s transformations

Question 3

Thermochemistry

Answer 3

The energy changes that take place during chemical reactions

Question 4

Matter

Answer 4

The physical material of the universe. Anything that Anything that occupies space occupies space and has mass has mass.

Question 5

Energy

Answer 5

• •Potential to perform work (Ch. 5)
• •Potential energy (Ch 5)
• •Kinetic energy (Ch. 5)
• •Heat (Ch. 5) Heat (Ch. 5)
• •Radiant energy (Ch. 6)
• •Chemical energy (Ch. 5)
• •Free energy (Ch. 19)
• •Electrical energy (Ch. 20) N l (Ch 21)

Question 6

Kinetic energy definition

Answer 6

Energy of motion

Question 7

Potential energy definition

Answer 7

stored energy

Question 8

Chemical energy

Answer 8

A form of potential energy where chemical bonds of a molecule act as the storage medium

Question 9

Chemicals release potential energy __ ____ ___ __ when they undergo a reaction to __ __ __ __ __ __ __ __

Answer 9

as heat, light, or work, form more stable products with more stable bonds

Question 10

Thermal energy (Heat) definition

Answer 10

Energy transferred from one object to another Energy transferred from one object to another as a result of a temperature difference

Question 11

Temperature definition

Answer 11

a measure of the kinetic energy of molecular motion

Question 12

How is temperature measured

Answer 12

by determining the direction and magnitude of heat flow from one object to another

Question 13

What is 1 joule?

Answer 13

2

Question 14

Joules per calorie

Answer 14

3

Question 15

calorie

Answer 15

one calorie is the amount of energy required to alorie is the amount of energy required to raise the temperature of one gram of water by one degree celsius

Question 16

Calorie (kcal)

Answer 16

• 1000 calories (1 kcal).
• The Calorie is what you see for food contents

Question 17

Law of conservation of mass:

Answer 17

atoms are not created or destroyed during chemical reactions.

Question 18

Exception to the law of conservation of mass

Answer 18

E=mc^2

Question 19

Law of conservation of energy

Answer 19

energy is not energy is not created or destroyed during reactions. It is converted from one form to another

Question 20

Exception to the Law of conservation of energy

Answer 20

E=mc^2

Question 21

The first law of thermodynamics The first law of thermodynamics

Answer 21

The energy of the UNIVERSE is constant

Question 22

The “system” definition

Answer 22

the components of a chemical reaction of interest

Question 23

The “system” components

Answer 23

1. • Reactants
2. • Products
3. • lnternal energy

• – Kinetic (thermal) energy
• – Potential (chemical) energy

Question 24

First law of thermal dynamics formula

Answer 24

4

Question 25

Energy out of system to surroundings: ____ sign _________

Answer 25

negative, exothermic

Question 26

Energy into system from surroundings: ____ sign _________

Answer 26

positive, endothermic

Question 27

Change in energy

Answer 27

5

Question 28

What determines how much internal energy a system has?

Answer 28

• • Chemical identity Chemical identity
• • Sample size
• • T t emperature
• • Pressure
• • Physical state (s, l, g)

Question 29

What temporal factor determines how much internal energy a system has?

Answer 29

• The amount of an internal energy a “system” has is dependent on it’s present condition (state).
• It is not dependent on the “system’s” past history

Answer 30

Ek=.5mv2

m in kg

v in m/s