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What is thermochemistry?

The study of heat changes that accompany chemical rxns & physical changes

1

Define heat

Sum total of the KE of all particles in a sample of matter

2

Where does heat flow from?

High concentration to low concentration

3

What is heat measured with?

Calorimeter

4

What is a calorimeter?

Contains water in an insulated vessel

5

Where does a rxn occur?

In a known mass of H2O

6

Heat absorbed or released by H2O is equal to what?

That absorbed OR released by a rxn

7

Define tempature?

Measures the average KE of particles in a sample of matter

8

What unit is tempature in?

Joules

9

What is KE formula?

1J=(n)(m)

10

What is one newton equal to?

1N=(kg)(m)/sec^2

11

What is 1J equal to?

(Kj)(m^2)/sec^2

12

Define specific heat

Amount of heat beg required to raise T of a substance by 1 degree Celsius or kelvin

13

What is the symbol for specific heat?

Cp

14

What are the units for Cp?

Joules/(g)(k)

15

What substance has the highest specific heat?

Water

16

What is waters specific heat?

4.18 joules/(g)(k)

17

Define heat capacity

The ability of a material to absorb heat

18

What is one I the specific heat calcs?

Cp=q/(m) TRIANGLE T

19

q=

(Cp)(m)(TRIANGLE T)

20

Triangle T=

Q/m•Cp

21

What heat of rxn AKA?

Enthalpy

22

Define heat of rxn

Amount of heat absorbed or released in a chem rxn

23

Heat of rxn is the difference...

In heat between the stored nrg of the reactions & that of the products

24

Define exothermic

Heat is released & feels hot

25

What is TRIANGLE H when exothermic?

Negative as heat is lost

26

Exothermic reactants have what?

Higher heat content than products

27

Define endothermic

Heat is absorbed

28

What is TRAINGLE H when endothermic?

Positive as heat is gained

29

Endothermic products have what?

Higher heat content than reactants

30

How do you determine endothermic heat?

TRIANGLE H is negative as heat is lost

31

When TRIANGLE H is a high negative value what's formed & how?

A stable compound
Vigorously & spontaneously

32

What is released when a product is formed?

Nrg released

33

What do reactants most commonly do?

Gain stability

34

When TRIANGLE H is a + or low negative what is true?

Unstable compound may form & may decompose violently

35

Define heat of combustion

Heat released by the complete combustion of 1 mol of a substance