TEST 1

Question 1

Definition of Heat

Answer 1

The exchange of thermal energy due to a temperature difference.

Question 2

Definition of Cold

Answer 2

The absence of heat

Question 3

Temperature

Answer 3

Quantitative measure of how hot something is. The measure of KE in particles.

Question 4

Endothermic

Answer 4

Energy is absorbed by the system from the surrounding. Negative Enthalpy.

Question 5

Exothermic

Answer 5

Energy is released from the system to the surrounding. Positive Enthalpy.

Question 6

1st Law of Thermo

Answer 6

energy is not created or destroyed

Question 7

Energy of the Universe = ?

Answer 7

Energy of the universe = Energy of the system + Energy of the surrounding

Question 8

a) Work =?

b) Unit of work?

Answer 8

a) F x D; Cross product of force and displacement
- PΔV; Negative Pressure times Volume

b) Joule (J)= kg m^2/s^2

Question 9

What is the System?

Answer 9

The molecule we want to study

Question 10

What is the surrounding(s)?

Answer 10

Everything else other than the system

Question 11

3 ways to transfer energy

Answer 11

1. Transfer heat
2. Work
3. Both heat and work

Question 12

Energy is?

Answer 12

The absolute ability to do work or transfer energy

E=q+w E=q(F*d) E=q+PΔV

Question 13

Pressure is?

Answer 13

P = F/A ; Pressure is Force/Area

Question 14

Volume is?

Answer 14

V=d*A; Volume is displacement * Area

Question 15

Work when gas expands?

Answer 15

W=-P(+ΔV); Work is negative

The system is doing work on the surrounding

Question 16

Work when gas is compressed?

Answer 16

W=-P(-ΔV); Work is positive

The surrounding does work on the system

Question 17

Definition of a State Function

Answer 17

The Property of an entity based only on its chemical or physical state. Doesn’t matter how it achieved the state.

Question 18

Definition of Thermal Energy

Answer 18

The portion of the internal energy of a system that is proportional to absolute temp. Comes from the vibration of molecules due to rise in temp.

Question 19

Isolated System

Answer 19

no flow

ex: a thermos

Question 20

Closed System

Answer 20

Only heat flow

ex: hot cup lid

Question 21

Open System

Answer 21

Matter and heat flow

ex: a cup without a lid

Question 22

Kinetic Energy

Answer 22

The energy of a moving object

Question 23

What is Enthalpy (ΔH)?

Answer 23

The energy flow in or out of the system

ΔH=ΔE+PΔV; Enthalpy equals Energy plus pressure times volume

ΔH=ΔE+W; Enthalpy equals Energy plus work done to or by the system

Question 24

Thermal Equilibrium

Answer 24

Heat flows from matter with high temp to matter with low temp until both objects are the same temp

Question 25

Enthalpy of Fusion (ΔHFusion)

Answer 25

Energy required to convert a mole of a solid substance to a liquid at its freezing/melting point

Question 26

Enthalpy of Vaporization (ΔHVap)

Answer 26

Energy required to convert a mole of liquid substance to a vapor at its boiling point.

Question 27

Heat Capacity (Cp)

Answer 27

The energy required to raise the temp of an object by 1-degree celsius at constant pressure. Measures sensitivity to temp changes. q=CpΔT q=mcsΔT q=ncpΔT

Question 28

Relationship between energy and Intermolecular forces

Answer 28

Energy is required to loosen intermolecular attractions. When KE is high enough to overcome intermolecular attractions, a phase change will occur.

Question 29

Formula for Heat transfer during a phase shift

Answer 29

q=m x cs x ΔT q=ΔH x #of moles q=ΔH x #of grams

Question 30

Enthalpy of reaction ΔH

Answer 30

ΔH=sum of ( nΔH(products)) - sum of (mΔH(reactants)) for enthalpies of reaction from bond energies: ΔH=sum of ΔH(bonds breaking) - sum of ΔH(bonds forming)

Question 31

Extensive Property

Answer 31

The value depends on the quantity of reactants/products

Question 32

Intensive Property

Answer 32

The value doesn't depend on quantity

Question 33

Calorimetry

Answer 33

measures enthalpy of reaction

Question 34

Constant pressure formula

Answer 34

q=mcΔT

Question 35

Constant Volume formula

Answer 35

q=CmΔT

Question 36

Bomb Calorimeter

Answer 36

sealed vessel with the system inside of it q=CΔT

Question 37

Methods used to estimate enthalpy of reaction by calculation

Answer 37

1. Hess's Law 2. Bond Energy Products and Reactants 3. Enthalpies of formation

Question 38

The equation for heated metal in water problems

Answer 38

``` q(metal) = -q(water) (mCΔT)metal = -(mCΔT)water ```

Question 39

Hess's Law

Answer 39

enthalpy of reaction for a process is equal to the sum of enthalpy values for reactions that add up to the reactions of interest.

Question 40

Standard Enthalpy of formation ΔH(f)

Answer 40

The enthalpy change that takes place when one mole of a substance is formed from its elements in their standard states.

Question 41

Lattice Energy

Answer 41

the energy required to separate a mole of ionic solid into gaseous ions. Cannot be measured empirically

Question 42

Born Harber Cycle

Answer 42

a series of reactions that represent the formation of an ionic compound from its elements.

Question 43

Spontaneous Processes

Answer 43

processes that proceed without outside influences

Question 44

Non-spontaneous Process

Answer 44

The process requires outside influence

Question 45

Entropy ΔS

Answer 45

Property for driving a reaction spontaneously forward. The measure of disorder of a system

Question 46

2nd Law of Thermo

Answer 46

for a spontaneous process there is always an increase in entropy in the universe if ΔS is >0; it is spontaneous if ΔS is <0; it is non spontaneous if ΔS is = 0; it is at equilibrium