Unit 3

Question 1

What is energy

Answer 1

The capacity to do work or produce heat

Question 2

Where is potential energy stored

Answer 2

stored in bonds

Question 3

What is thermal energy

Answer 3

total amount of kinetic energy in a system measured in joules

Question 4

What is heat and its symbol

Answer 4

thermal energy transferred between two systems symbol is q

Question 5

What is heat capacity and its symbol

Answer 5

amount of heating necessary to change the temperature of an object (depends on the amount of stuff) symbol is C

Question 6

What is specific heat and its symbol

Answer 6

heat capacity per gram symbol is c

Question 7

What is enthalpy and its symbol

Answer 7

thermal energy absorbed or released by a system that is free to do work symbol is H

Question 8

What is enthalpy when the rxn is exothermic and endothermic

Answer 8

negative for exothermic and positive for endothermic

Question 9

What is a stipulation of the enthalpy of formation

Answer 9

element being calculated needs to be only one mol so others might be in fractions

Question 10

What is the standard enthalpy of formation of elements in their natural state

Answer 10

zero

Question 11

What is bond energy and its symbol

Answer 11

the energy required to break a bond symbol is D

Question 12

What type of bonds are usually shorter

Answer 12

Stonger bonds

Question 13

What types of bonds are stonger

Answer 13

triple bonds then double then single

Question 14

What is lattice energy and its symbol

Answer 14

e required to pull ions apart symbol is delta H sub latt

Question 15

What is entropy and its symbol

Answer 15

disorder within a system symbol is s

Question 16

When is entropy favored or disfavored

Answer 16

when entropy is potive it is favored when its negative its disfavored

Question 17

What is free energy and its symbol

Answer 17

maximum amount of work a system can do spontaneously symbol is G

Question 18

What will free energy be when a reaction is spontaneous and not spontaneous

Answer 18

when negative the rxn is spontaneous and when postive the rxn is not spontaneous

Question 19

When enthalpy is negative and entropy is positive what will free energy be?

Answer 19

negative

Question 20

When enthalpy is positive and entropy is negative what will free energy be?

Answer 20

positve

Question 21

Under what conditions does free energy depend on temperature

Answer 21

when enthalpy and entropy are both negative and positive

Question 22

When an endothermic reaction occurs, what bonds are broken and what ones occur?

Answer 22

Strong bonds are broken while weak ones form

Question 23

When an exothermic reaction occurs what bonds are broken and what ones occur?

Answer 23

Weak bonds are broken while strong ones form

Question 24

When do molecules have a greater freedom of movement?

Answer 24

when pressure decreases

Question 25

What is the kinetic theory

Answer 25

Gas particles are in constant, random motion. Pressure is a result of gas particles colliding with walls of a container. Volume of the gas particles themselves is assumed to be negligable. Gas particles are neither attracted to nor repelled by each other. The average kinetic energy of a sample of gas particles is proportional to temperature.

Question 26

What is velocity dependent on and what are their relationships

Answer 26

temperature increases as velocity does and molar mass increases as velocity decreases

Question 27

What is kinetic enegy dependent on and what is its relationship

Answer 27

temperature increases as kinetic energy does

Question 28

What is the mean free path

Answer 28

distance that a gas particle travels before hitting another gas particle

Question 29

What is diffusion

Answer 29

mixing of gases

Question 30

What is effusion

Answer 30

rate at which gases expand into a vacuum through a small hole

Question 31

When do real gases deviate from ideal behavior and why

Answer 31

At high pressure since as pressure increases, the volume of a gas particle becomes more significant thus, moving away from the ideal gas law. Low temperature since gas particles are attracted to each other but at low temperatures, particle attraction slows down thus, decreasing pressure which is not ideal

Question 32

When work is negative and positve is work being done by or on the system?

Answer 32

When work is negative, work is being done by the system. When work is positive, work is being done on the system

Question 33

What must delta V be in order for work to be negative

Answer 33

positive

Question 34

What must delta V be in order for work to be positive

Answer 34

negative

Question 35

When a rxn is endothermic what are the enthalpy and heat signs

Answer 35

positive and positive

Question 36

When a rxn is exothermic what are the enthalpy and heat signs

Answer 36

negative and negative

Question 37

What is the lattice energy trend

Answer 37

increases up and to the right