2020 Mod 13

Question 1

In a chemical reaction, where is the potential energy? Where is the kinetic energy

Answer 1

The potential energy is in the bonds between the molecules

The kinetic energy is in the heat absorbed or released

Question 2

If a chemical reaction is positive delta H Will the beaker containing the reaction feel hot or cold once the reaction is finished?

Answer 2

Cold

Question 3

Why is Hesses law a more exact with the turn determining delta H then techniques that use bond energy’s

Answer 3

Has his law takes into account the different phases

Question 4

What is a state function? Give two examples

Answer 4

A quantity that depends solely on the final destination not on the way got there

Enthalpy and Gibbs free energy are two examples

Question 5

What substances will have a delta HF degree of zero?

Answer 5

Elements in their elemental form

Question 6

If you have 2 50.0 KG block of copper And one temperature is 50° C wow the other temperature is 25° C which will have more entropy

Answer 6

The warmer one

Question 7

If a chemical reaction is exothermic but has a negative S what could you do to the temperature to make it possible to re-run the reaction

Answer 7

Delta G equals delta H minus teetimes Delta S

Lower the temp to make T times Delta S smaller

Question 8

What way will we think of energy and chemical reactions

Answer 8

When I chemical reaction is exothermic, energy will be thought of as a product in the reaction. If the reaction is endothermic, energy will be considered a reactant

Question 9

Change in enthalpy delta H

Answer 9

The energy change that accompanies a chemical reaction

Question 10

How many calories how many joules fit in one calorie

Answer 10

1 cal equals 4.184 Joules

Question 11

When is Delta H positive and when is it negative

Answer 11

Delta H is positive for endothermic reactions, and delta H is negative for exothermic reactions

Question 12

Endothermic

Answer 12

Delta H is positive heat is absorbed potential energy that is stored is greater than the reactants

Question 13

Exothermic reactions

Answer 13

Delta H is negative heat is released the potential energy stored in the reactions products is less than the reactants

Question 14

Is energy both absorbed and released during the course of a reaction

Answer 14

Yes

Question 15

Equation 13.2

Answer 15

Delta H equals energy required to break bonds minus energy released when bond form

Question 16

Hess’s law

Answer 16

Enthalpy is a state function

Question 17

State function

Answer 17

Eastate function is any quantity that depend solely on the final destinations not on the way it got to that destination

Question 18

Enthalpy of formation delta HF

Answer 18

The delta H of a formation reaction

Question 19

What is standard conditions

Answer 19

Room temperature 25°C

And 1.00 ATM

Question 20

What is the symbol of standard enthalpies of formation

Answer 20

Delta HF degrees

Question 21

Equation 13.3

Answer 21

Delta H degrees equals the sum of delta HF degrees product minus the sum of delta HF degrees reactant

Question 22

What is the standard entropy of the formation of an element in its elemental form

Answer 22

The standard enthalpy of formation of an element in it elemental form is zero

Question 23

What is an energy diagram

Answer 23

A picture of energy associated with a chemical reaction

Question 24

Activation energy

Answer 24

The energy necessary to start a chemical reaction

Question 25

Entropy

Answer 25

A measure of the disorder that exist in any system

Question 26

The second law of thermodynamics

Answer 26

The entropy of the universe must always either increase or remain the same I can never decrease

Question 27

What is the relative Entropy of the phases of matter

Answer 27

The solid state has the least amount of entropy associated with it. The entropy of the liquid state is higher in the entropy of the gaseous state is the highest of all

Question 28

How does entropy react with temperature

Answer 28

The entropy of a system increases with increasing temperature

Question 29

What problem exist in nature

Answer 29

The enthalpy of a system increases as the matter it contains increases

Question 30

Equation 13.4

Answer 30

Delta S universe is greater than or equal to zero

Question 31

Do all substances substances even elements have an absolute entropy

Answer 31

Yes

Question 32

Gibbs free energy

Answer 32

Delta G equals delta H minus tee times Delta S

Question 33

If delta H is less than zero

Answer 33

then the reaction is consistent with the second law and is spontaneous

Question 34

If delta G is greater than zero

Answer 34

then the reaction cannot proceed because it violates a second law