Thermochemistry

Question 0

define work

Answer 0

energy used to cause an object that has mass to move

Question 1

Define Energy

Answer 1

the ability to do work or transfer heat

Question 2

define heat

Answer 2

energy is used to cause the temperature of an object to rise

Question 3

Define kinetic energy and provide the equation

Answer 3

energy an object possess by virtue of its motion

E - 1/2 mv^2

Question 4

Define potential energy and provide the equation

Answer 4

energy an object possess by vitue of its position or chemical composition
E = kQ1Q2/d

Question 5

What’s the standard SI unit of Energy

Answer 5

joule

j=kg m^2 /s^2

Question 6

Define “System”

Answer 6

The molecules wanted to study

Question 7

Define “surroundings”

Answer 7

everything that’s not the system

Question 8

If q is positive, what is the reaction?

Answer 8

Endothermic

Question 9

If q is negative, what is the reaction conisdered?

Answer 9

Exothermic

Question 10

First Law of Thermodynamics

Answer 10

Energy is neither created nor destroyed

Question 11

Define Internal Energy

Answer 11

the sum of all kinetic and potential energies of all components of the system

Question 12

Define Endergonic

Answer 12

When the change in internal energy is greater than 0 (the system absorbed energy from its surroundings)

Question 13

Define exergonic

Answer 13

When the change in internal energy is less than 0 *(the system released energy to the surroundings)

Question 14

What the equation to fine internal energy

Answer 14

E= q + w

Question 15

Define Enthalpy

Answer 15

The heat of a reaction

H = E + PV

Question 16

Define calorimetry

Answer 16

The measurement of heat flow

Question 17

Define heat capacity

Answer 17

The amount of energy required to rais the temperature of a substance by 1K (1C)
C = heat absorbed / increase in temperatrue

Question 18

Define specific heat capactiy

Answer 18

The amount of energy required to raise the temperatue of 1 g of a substance by 1 K
s = q / m (change in T)

Question 19

Hess’s law states:

Answer 19

if a reaction is carried out in a series of steps, (delta)H for the overall reaction will equal to the sum of the enthalpy changes for the individual steps

Question 20

hess’s law is calculated how?

Answer 20

(delta)H = the sum of the enthalpy of the products - the sum of the enthalpy of the reactants

Question 21

Define a spontaneous processes

Answer 21

those that can proceed without any outside intervention

Question 22

Processes that are spontaneous in one direction are ________________ in the reverse direction

Answer 22

nonspontaneous

Question 23

Define Entropy (S)

Answer 23

a thermodynamic function that describes the number of arrangements (positions and/or energy levels) that are available to a system existing in a given state; can be thought of as a measure of the randomness of a system

Question 24

Second Law of Thermodynamics

Answer 24

The second law of thermodynaics states that the entropy of the universe increases for spontaneous processes and the entropy of the universe does not change for reversible processes

Question 25

If (delta) S univ is positive

Answer 25

then entropy of the universe increases and the process is spontaneous

Question 26

if (delta) S univ is 0

Answer 26

the process has no tendency to occur and the system is at equilibrium

Question 27

Entropy tends to increase with increases in

Answer 27

Tempreature
Volume
The number of independently moving molecules
When a solid is dissolved in a solvent

Question 28

delta S =

Answer 28

The sum of the entropy of products - the sum of the entropy of reactants

Question 29

What is Gibbs free energy?

Answer 29

-T(delta)S universe

Question 30

When delta S is positive Gibbs free energy (delta G)

Answer 30

negative

Question 31

Gibbs is negative

Answer 31

Reaction is spontaneous

Question 32

Gibbs at 0

Answer 32

The system is at equilibrium

Question 33

Gibbs is positive

Answer 33

the reaction is spontaneous in the reverse direction