Exam 2 Lecture 2 Thermodynamic

Question 1

What determines how much internal energy a system has?

Answer 1

• Chemical identity Chemical identity
• • Sample size
• • Temperature
• • Pressure
• • Physical state (s, l, g)

Question 2

State function definition

Answer 2

• A function or property whose value depends only on the present state of the system, not the path used to arrive at that condition

Question 3

Examples of state functions

Answer 3

– Age – Weight – Location – Elevation

Question 4

If the system returns to its original conditions, then for a state function of that system…

Answer 4

the overall change is zero

Delta state=initial state-final state=0

Question 5

1

Answer 5

C. because you can burn a variable amount of calories depending on the nature of your workout

Question 6

Explain why location is a state function

Answer 6

2

Question 7

Explain why elevation is a state function

Answer 7

3

Question 8

Internal energy of a nonreacting system is a state function Internal energy of ________

Answer 8

a nonreacting system is a state function

Question 9

The energy change that occurs during a chemical reaction is______

Answer 9

Delta E: a state function

Question 10

What does delta E equal?

Answer 10

4

Question 11

What does q mean 4

Answer 11

5 heat

Question 12

what does w mean 4

Answer 12

5 work

Question 13

Example of electron flow with no conservation of energy

Answer 13

6 undamned waterfall (energy converted to sound and heat)

Question 14

Why is q not a state function?

Answer 14

Contributions of q and w can vary depending on how you set the experiment up (pressure or no pressure)

Question 15

why is w not a state function?

Answer 15

Contributions of q and w can vary depending on how you set the experiment up (pressure or no pressure)

Question 16

Example of electron flow with conservation of energy

Answer 16

7 hydroelectric power

Question 17

Potential energy has proportionate relationships to

Answer 17

8

Question 18

Kinetic energy has proportionate relationships to

Answer 18

8

Question 19

Chemical potential energy:

Answer 19

stored in bonds

Question 20

– Thermal energy:

Answer 20

kinetic energy of molecules

Question 21

– Heat: is ___ energy

Answer 21

radiant

Question 22

Work is ___

Answer 22

some form of movement

Question 23

——> +energy

Answer 23

Delta E = -energy

Question 24

+energy—–>

Answer 24

Delta E= +energy

Question 25

________is necessary for work to occur in a chemical reaction

Answer 25

A difference in pressure

Question 26

Describe Delta E in changes in energy and q and w

Answer 26

9

Question 27

Define Enthalpy in terms of p and q

Answer 27

10 In enthalpy, no work is performed

Question 28

If enthalpy is negative

Answer 28

11

Question 29

If enthalpy is positive

Answer 29

11

Question 30

ΔH depends on the _______ of reactants and products

Answer 30

physical states

Question 31

13

Answer 31

14

Question 32

How to determine ΔH experimentally

Answer 32

calorimetry

Question 33

How to determine ΔH experimentally

Answer 33

calorimetry

Question 34

heat Capacity formula

Answer 34

15

Question 35

Specific heat formula

Answer 35

16

Question 36

By __________,________, ________, you can determine ΔH for the reaction

Answer 36

the mass of the water, the temperature change, and the specific heat of the surroundings (water)

Question 37

Steps to determine ΔH experimentally

Answer 37

17

Question 38

1 calorie is the same as

Answer 38

the specific heat of water

Question 39

define bomb calorimeter

Answer 39

Volume change is minimized:
a device for determining heats of combustion by igniting a sample in a high pressure of oxygen in a sealed vessel and measuring the resulting rise in temperature: used for measuring the calorific value of foods.

Question 40

If no work is performed, then ΔH=

Answer 40

ΔE

Question 41

If there is gas generation or gas consumption, then ΔH doesn’t =

Answer 41

ΔE

Question 42

Model why physical state is important to energy used in a reaction

Answer 42