Physical Properties and Changes of Matter

Question 1

Describe matter (4)
* what is matter
* what are 2 things that determine matter
* what is matter made of in the simplest terms
* what is NOT considered matter?

Answer 1

• matter is anything that has mass (quantity or measurement of matter) or volume (amount of space an object occupies)
• distance b/w the mlcs and speed of mlcs moving
• atoms / mlcs
• forms of energy (light, heat, sound)

Question 2

What are the two types of properties of matter? Explain and give examples.

Answer 2

• physical : observed and measured - divided into intensive and extensive

Intensive: DO NOT depend on the amount of matter or the sample size (ie. color, density = mass/volume, boiling/ melting point, solubility)

Extensive: DOES depend on the amount of matter or sample size (higher the sample size= higher the property) (ie. size, volume, energy, mass- amount of matter in object, weight - gravitational pull of earth on object)

• chemical: observed and measured when a substance changes composition (ie. H2 [g] burned in O2 creates H2O [l]= chemical property of H2) (ie. reactivity, flammability, combustibility)

Question 3

What is the definition of a substance?

Answer 3

things that have a uniform and definited composition

Question 4

How do you calculate density?
What type of property of matter is density?

Answer 4

• mass / volume [ g/ cm^3]
• intensive physical property

Question 5

Define triple point

Answer 5

the temperature and pressure in which the s, l, g of a pure substance is able to co-exist in equilibrium

Question 6

Describe solids

Answer 6

• mlcs are tightly packed together –> vibration motion
• hard and rigid –> FIXED shape and volume

Question 7

Describe liquids

Answer 7

• mlcs are father apart and so are able to move freely (vibration and translational motion) and quickly
• FIXED volume and INdefinite (NO definite) shape, which means will mold to shape of container

Question 8

Describe gases

Answer 8

• mlcs are very far apart, so they can move very freely and quickly
• NO FIXED shape (NO definite shape) or volume and assumes the shape of the container

Question 9

What are the phase changes from S–> L –> G –> S

Answer 9

• melting
• vaporization (evaporation)
• deposition

Question 10

What are the phase changes from S–> G–> L–> S?

Answer 10

• sublimation
• condensation
• freezing

Question 11

Describe the difference in shape b/w liquids and gases

Answer 11

Both have NO FIXED shape
* liquid: INdefinite shape
* gases: NO definite shape

Question 12

• List the order of KE of the different states of matter
• Which element has the highest KE? What state of matter is it in?

Answer 12

gas&raquo_space; liquid > solid
He (g) has the HIGHEST KE

Question 13

Cohesive forces of
* S
* L
* G

Answer 13

• S: Strong
• L: can be overcome
• G: weak

Question 14

Density of
* S
* L
* G

Answer 14

• S: high
• L: high
• G: low

Question 15

Compressibility of
* S
* L
* G

Answer 15

• S: none
• L: none
• G: high

Question 16

Phase changes are regulated by what?

Answer 16

• temperature and atm pressure (inversely related)
• inc temp and dec atm pressure –>speed up vaporization (evaporation)

Question 17

Solid water is ___ dense than liquid water

Answer 17

• less

remember ice floats

Question 18

Describe the heating curve (have picture in mind)

Answer 18

in ipad

Question 19

Describe the cooling curve (have picture in mind)

Answer 19

in ipad

Question 20

During phase changes in a heating/ cooling curve, what stays the same?

Answer 20

• temperature

Question 21

What is it called when gas –> solid and when solid –> gas?

Answer 21

• deposition
• sublimation

Question 22

What is it called when solid –> liquid and when liquid –> solid

Answer 22

• melting
• freezing

Question 23

What is it called when liquid –> gas and when gas–> liquid?

Answer 23

• vaporization (evaporation)
• condensation

Question 24

In between phase changes in the heating curve, what is happening to the cohesive forces?

Answer 24

decreasing

Question 25

In between phase changes in the cooling curve, what is happening to the cohesive forces?

Answer 25

increasing

Question 26

# heating curve * In the heating curve, what are the 3 phase changes involved? * During the phase changes, what is happening?

Answer 26

* melting (S--> L), vaporization (evaporation) (L --> G), sublimation (S --> G) * mlcs are **absorbing heat**, which causes mlcs to spread apart from each other **BUT temp is the same**

Question 27

# cooling curve * In the cooling curve, what are the 3 phase changes involved? * During the phase changes, what is happening?

Answer 27

* condensation (G --> L), freezing (L --> S), deposition (G --> S) * mlcs are **releasing (subtracting, losing) heat**, which makes mlcs come closer together **BUT the temp is the same**

Question 28

What is another name for the melting phase? What is another name for the vaporization (evaporation) phase?

Answer 28

* latent heat of fusion * latent heat of vaporization

Question 29

Matter can be split into what 2 general categories?

Answer 29

* pure substances * mixture

Question 30

Describe pure substances (including what it can be further split into and describe those)

Answer 30

* they have the same chemical composition throughout * can be split further into elements and compounds, which are all mlcs elements: found on periodic table mlcs: 2 or more elements in definite proporitions (ie. H2O, NaCl)

Question 31

Describe mixtures (including what it can be further split into and describe those)

Answer 31

* 2 or more pure substances combined * can be split further into homogenous or heterogenous) homogenous: **uniform** distribution and **NO distinct boundaries** (ie. salt water and slns) heterogenous: **varied** distribution and **HAVE** distinct boundaries (ie. oil and water SEPARATE)

Question 32

What is an alloy (include an example)

Answer 32

* a new type of metal made by combining solid slns of other metals * bronze (from copper and tin combining)

Question 33

What is the critical point?

Answer 33

when the liquid and gas phase have the same density , so they are indistinguishable

Question 34

If we mix a sln in ice water, what are we trying to do?

Answer 34

**slow the rate** of rxn by **reducing the collison** of mlcs

Question 35

What are 3 other extensive properties I didn't learn about in my notes?

Answer 35

* entropy * number of moles * electrical charge

Question 36

What is 1 other intensive property I didn't learn about in my notes?

Answer 36

temperature

Question 37

What are some additional examples of homogenous mixtures beside salt water and slns?

Answer 37

milk, air, blood, black coffee

Question 38

What are some additional examples of heterogenous mixtures?

Answer 38

tea with boba and pizza and *cereal w/ milk*

Question 39

What are the new definitions of mass and volume i learned?

Answer 39

* mass: the **number** of mlcs in an obj * volume: the amount of **space** the mlcs in an obj occupy

Question 40

What is the SI unit of mass?

Answer 40

kg

Question 41

How many states of matter are there and what are they?

Answer 41

* 4 * S, L, G, plasma (plasma is least common)

Question 42

Matter can exist in ____ states depending on the ____

Answer 42

* different * environment