Math Review for Chemistry

Key Ideas

Matter is classified as a pure substance or as a mixture of substances. (3.1q)
The three phases of matter (solids, liquids, and gases) have different properties. (3.1kk)
A pure substance (element or compound) has a constant composition and constant properties throughout a given sample, and from sample to sample. (3.1r)
Elements cannot be broken down by chemical change. (3.1u)
Mixtures are composed of two or more different substances that can be separated by physical means. When different substances are mixed together, a homogeneous or heterogeneous mixture is formed. (3.1s)
The proportions of components in a mixture can be varied. Each component in a mixture retains its original properties. (3.1t)
Differences in properties such as density, particle size, molecular polarity, boiling point and freezing point, and solubility permit physical separation of the components of the mixture. (3.1nn)
A solution is a homogeneous mixture of a solute dissolved in a solvent. The solubility of a solute in a given amount of solvent is dependent on the temperature, the pressure, and the chemical natures of the solute and solvent. (3.1oo)
Energy can exist in different forms, such as chemical, electrical, electromagnetic, thermal, mechanical, and nuclear. (4.1a)
Heat is a transfer of energy (usually thermal energy) from a body of higher temperature to a body of lower temperature. Thermal energy is the energy associated with the random motion of atoms and molecules. (4.2a)
Temperature is a measurement of the average kinetic energy of the particles in a sample of material. Temperature is not a form of energy. (4.2b)
The concepts of kinetic and potential energy can be used to explain physical processes that include: fusion (melting), solidification (freezing), vaporization (boiling, evaporation), condensation, sublimation, and deposition. (4.2c)
A physical change results in the rearrangement of existing particles in a substance. A chemical change results in the formation of different substances with changed properties. (3.2a)
Chemical and physical changes can be exothermic or endothermic. (4.1b)
The structure and arrangement of particles and their interactions determine the physical state of a substance at a given temperature and pressure. (3.1jj)
The placement or location of elements on the Periodic Table gives an indication of physical and chemical properties of that element. The elements on the Periodic Table are arranged in order of increasing atomic number. (3.1y)
Elements can be classified by their properties and located on the Periodic Table as metals, nonmetals, metalloids (B, Si, Ge, As, Sb, Te), and noble gases. (3.1v)
Elements can be differentiated by their physical properties. Physical properties of substances, such as density, conductivity, malleability, solubility, and hardness, differ among elements. (3.1w)
Elements can be differentiated by chemical properties. Chemical properties describe how an element behaves during a chemical reaction. (3.1x)
Some elements exist in two or more forms in the same phase. These forms differ in their molecular or crystal structure, and hence in their properties. (5.2f)
Matter

Do Now: Complete the following Pre-test. Put T for true statements and F for false statements in the space provided.

____1. Matter is anything that has mass.

____2. A spaceship ceases to be matter when it is in space because it has no weight.

____3. Air can be weighed.

____4. Heat has weight.

____5. Both air and heat are matter.

____6. Matter takes up space.

____7. Air occupies space.

____8. Light takes up space.

____9. Light is matter.

____10. Matter can be in different shapes.

____ 11. Matter can be in different phases.

____12. Water has no definite shape therefore it is not a matter.

____13. A solid has a definite shape.

____14. You cannot change the shape of a solid.

____15. You can compress water to force it to occupy less space.

____16. A glass is inverted over a basin of water and slowly inserted into the water. However,

the water does not enter the glass. This experiment proves that air takes up space.

____17. Air will expand to fill the space available.

____18. Matter can exist in three states: solid, liquid and gas.

____19. Iron combines with oxygen in moist air to form iron oxide, or rust. This change is

called a chemical change.

____20. When water changes to steam it undergoes a chemical change.

Bottom of Form

Matter vs. Not Matter

Can you recognize matter when you see it? What makes matter different from that which is not matter? A light bulb, for example, is matter. The electricity that makes it glow is not. What is the difference? All matter has certain characteristics in common that separate it from whatever is not matter. Can you tell which is which? Get together with your lab group and try. You will be given a card with a list of six items. Three are matter and three are not.

1. Try to classify the items on the card properly. Write your conclusions in the table below.

MATTER / NOT MATTER

2. Describe the characteristics all the items you classified as MATTER have in common that make them different from the items you classified as NOT MATTER.

Matter- Anything that has mass and volume (takes up space)

1. An element is the simplest form of matter.

• It cannot be decomposed

• Elements are made up of tiny particles called atoms

• There are 7 diatomic elements

2. A compound is a substance made up of two or more elements in a fixed proportion

• compounds are made up of particles called molecules

3. A mixture is a combination of two or more substances (elements or compounds)

• It can be separated into components by physical methods

• It can be homogeneous or heterogeneous

Matter Activity

Station Number/
Identity of Substance / Description/Observations / Classification
(Element,
Compound,
Homogeneous Mixture, Heterogeneous Mixture) / How do you know?
1
2
3
4
5
6
7
8
9
10
11
12
13
14

Questions:

How could you tell a substance is an element?

What phases can elements be in?

How could you tell a substance is a compound?

What phases can compounds be in?

How could you tell a sample is a mixture?

What phases can mixtures be in?

How do you know the difference between a homogeneous and heterogeneous mixture?

Particle Diagrams of Matter

Particle diagrams are used to illustrate states and forms of matter. Typically, a particular type of atom is shown as a small circle of one color or shade.

A diagram of an elementwould contain only one type of atom.

A compoundwould contain two or more types of atoms attached in a fixed ratio

Amixture would contain one or more elements and one or more compounds.

Check your understanding:

IDENTIFY THE FOLLOWING AS A pure element, pure compound or mixture of ???

______

Elements, Compounds, and Mixtures Notes

There are 2 types of PURE SUBSTANCES. They can be either an element or a compound.

1.)Element: It is the simplest form of matter that can exist under lab conditions.

Elements cannot be separated into simpler substances.
They are represented by a symbol; ONE Capital Letter. (Each capial letter represents one element.) Sometimes a lowercase letter is used as well.
Elements are shown on the Periodic Table

Elements can be classified as metals (left of staircase), nonmetals (right of staircase), or metalloids.
Transition metals, groups 3-12, can create colored compounds and solutions.

•There are some elements (only 7!) that exist in nature only as diatomic elements.

Br2, I2, N2, Cl2, H2, O2, F2

That means there are two atoms of one kind stuck (bonded) together so you should always use a co-efficient of 2 when you see them in an equation!
Examples of particle diagrams that would represent diatomic elements:

2.) Compound: Two or more elements chemically combined with each other.

Compounds can be separated into simpler substances.
A compound has a fixed composition. It is always the same.
Formulas for compounds are written in a certain way.

EXAMPLES:H2O CO2 NaCl

The little numbers directly following an element symbol are called subscripts. This tells you how many atoms of that element are in the compound.

EXAMPLES: H2O CO2 NaCl

(2 H’s and 1 O) (1 C and 2 O’s) (1 Na and 1 Cl)

A common mistake by students such as yourself happens in compounds like CO2. The 2 goes ONLY TO THE O… NOT TO THE C (as shown above in the formula and below in the picture.)
We can draw particle diagrams of these three compounds as follows:

H2O CO2 NaCl

Compounds are made up of molecules (a specific ratio of chemically combined atoms).

Amixture is a blend (physical change) of two or more substances.

Homogeneous Mixtures are uniform throughout

Examples: salt in water, air

Heterogeneous Mixtures are non-uniform

Examples: chunky chicken soup, dirt in water

Homogeneous and Heterogeneous are bothrelative terms. This means that some of your answers will depend on your prior experiences and knowledge. As long as you can defend/explain why you answered your question the way you did, it is acceptable.

Na + S is a mixture. Likewise Na2S + KCl is a mixture

Metals, Nonmetals, and Metalloids Activity

Directions: For each element, write observations and given details and determine if they are metals, nonmetals, or metalloids (semimetals). Then complete the rest of the table.

Observations/Details / M, NM, or SM / Element / Period / Group
1
2
3
4
5
6
7
8
9
10
11
12
13
14

Metals

Nonmetals

Metalloids
Metals and Groups/Periods Questions

Math Review for Chemistry

1. WhichthreegroupsofthePeriodicTablecontainthemostelementsclassifiedasmetalloids(semimetals)?

A) 1, 2, and 13 B)2,13,and14C)14, 15, and16D) 16, 17,and18

2. Whichelementshavethemostsimilarchemicalproperties?

A) Kand NaB)KandClC)K andCaD) Kand S

3. ThemetalloidsthatareincludedinGroup15areantimony and

A)NB)P C) As D) Bi

4.Whichsequenceofatomicnumbersrepresentselementswhichhavesimilarchemicalproperties?

A) 19, 23, 30, 36 B)9,16, 33, 50C)3, 12, 21, 40D) 4, 20, 38, 88

5. WhichgroupcontainselementscomposedofdiatomicmoleculesatSTP?

A) 11B)2C) 7D) 17

6. OnthePeriodicTable,anelementclassifiedasasemimetal(metalloid)canbefoundin

A) Period6,Group 15 B)Period2,Group14C)Period 3,Group16 D) Period4,Group15

7. Whichelementisconsideredmalleable?

A)gold B)hydrogenC)sulfur D) radon

8. Whichelementismalleableandconductselectricity?

A) iron B)iodineC)sulfur D) phosphorus

9. Whichelementismalleableandductile?

A) SB)Si C)Ge D) Au

10. Whichelementisbrittleanddoesnotconductheator electricity?

A) S(s) B)Mg(s) C)Al(s)D) K(s)

11. Whichelementisanactivenonmetal?

A) Neon B)oxygen C)zincD)chromium

12. Whichcharacteristicsdescribemostsolid nonmetals?

A) Theyaremalleableandhavemetallicluster.C) Theyarebrittleandhavemetallicluster.

B) Theyaremalleableandlackmetallicluster.D) Theyarebrittleandlackmetallicluster.

13. Whichelementisametalloid?

A) Al B)ArC) AsD) Au

14. Theelementarsenic(As)hasthepropertiesof

A) metals,onlyB) nonmetals,onlyC) bothmetalsandnonmetals

15. Whichelementisnotametalloid?

A)arsenicB)boronC)siliconD)sulfur

16. Whichcompoundformsagreenaqueoussolution?

A)RbClB)CaCl2 C)NiCl2

General Chemistry Unit 2: Matter

Matter Practice

Directions: After each statement below, choose the letter of the word that applies from the list below.

a. mattere. compound

b. substancef. heterogeneous mixture

c. mixtureg. homogeneous mixture

d. element

_____ 1) cannot be chemically decomposed

_____2) components can be combined in any ratio

_____ 3) components must be combined in a specific, fixed ratio that can never change

_____ 4) has mass and volume

_____5) chemically combined to produce new substance with totally new properties

_____ 6) substances are physically combined, unevenly spread throughout

_____7) substances are physically combined, evenly spread throughout

_____ 8) combining substances where each substance retains its individual properties

_____ 9) manganese

_____ 10) Al2(SO4)3

_____ 11) sand in water

_____ 12) physically combined, physically separated

_____ 13) since the substances retain their individual properties, they can be separated based on their

unique physical properties

_____ 14) can’t be physically decomposed, but can be chemically decomposed

Matter Practice

Classify each of the following with the combination of terms listed below.

pure substance – element mixture – homogeneous

pure substance – compound mixture – heterogeneous

HCl (aq) 2. sugar (C11H22O11) 3. KBr (s)4. Soil

5. Cl2 (g) 6. water 7. CH2(OH)2 (aq) 8. Sodium

9. Hg (l)10. iron oxide 11.NH3 (l)12. salt water

13. Matter that is composed of two or more different elements chemically combined in a fixed proportion is classified as

(1) a compound (2) an element (3) a mixture (4) a solution

14. A compound differs from an element in that a compound

(1) is homogeneous

(2) has a definite composition

(3) has a definite melting point

(4) can be decomposed by a chemical reaction

15. A compound differs from a mixture in that a compound always has a

(1) homogeneous composition

(2) maximum of two elements

(3) minimum of three elements

(4) heterogeneous composition

16. A heterogeneous material may be

(1) an element

(2) a compound

(3) a pure substance

(4) a mixture

17. Which statement is an identifying characteristic of a mixture?

(1) a mixture can consist of a single element

(2) a mixture can be separated by physical means

(3) a mixture must have a definite composition by weight

(4) a mixture must be homogeneous

18. Which must be a mixture of substances?

(1) solid (2) liquid

(3) gas(4) solution

19. Which substance can be decomposed by chemical means?

(1) aluminum (2) octane (3) silicon (4) xenon

20. Which substance can be decomposed by chemical means?

(1) ammonia (2) oxygen

(3) phosphorus (4) silicon

21. Which substance can not be broken down by a chemical reaction?

(1) ammonia (2) argon (3) methane (4) water

22. Two substances, A and Z, are to be identified. Substance A can not be broken down by a chemical change. Substance Z can be broken down by a chemical change. What can be concluded about these substances?

(1) Both substances are elements.

(2) Both substances are compounds.

(3) Substance A is an element and substance Z is a compound.

(4) Substance A is a compound and substance Z is an element.

23. Which terms are used to identify puresubstances?

(1) an element and a mixture

(2) an element and a compound

(3) a solution and a mixture

(4) a solution and a compound

24. Two different samples decompose when heated. Only one of the samples is soluble in water. Based on this information, these two samples are

(1) both the same element

(2) two different elements

(3) both the same compound

(4) two different compounds

25. Tetrachloromethane, CCl4, is classified as a

(1) compound because the atoms of the elements are combined in a fixed proportion

(2) compound because the atoms of the elements are combined in a proportion that varies

(3) mixture because the atoms of the elements are combined in a fixed proportion

(4) mixture because the atoms of the elements are combined in a proportion that varies

Drawing Particle Arrangements

Draw a diagram of a:

pure diatomic pure diatomic mixture of mixture of mixture of

element compound two elementsan element & two diatomic

a compound elements &

a compound

1.) In terms of composition/type of atoms, what is the difference between a monatomic element, a diatomic element, and a diatomic compound?

2.) Use the following key for parts a-c.= element X = element Z

a.) 8 atoms of element X in gaseous form b.) 4 molecules of compound X2Z in liquid form

c.) Homogeneous mixture of element Z with element X (10 atoms of each element).

Separating Mixtures

Since mixtures are made by physicallycombining 2 or more pure substances together, we use physicaltechniques to separate them. The technique used depends on what phase or state of matter the components are.

Fitration-solid and a liquid
Phase change-distillation, evaporation, etc.
Separatory funnel-two immiscible liquids
Various physical means such as magnet, tweezers, sieve -two solids
Chromatography – density and particle size differences

Separation Apparatus / Type of Separation (Physical or Chemical) / Description of Technique / What types of
Matter will it separate?
Filtration / PHYSICAL / Undissolved particles remain on filter paper (filtrate flows through filter paper) / HETEROGENEOUS mixtures (ex: sand water)
*Can also centrifuge
Watch Glass Evaporation
/ PHYSICAL /

Separate solute (dissolved solid) from solvent (liquid) by boiling solution
Solute escapes
Very limited precision

/ HOMOGENEOUS mixture (solution)
Distillation
/ PHYSICAL /

Separate solute from solvent by boiling solution and recondensing in receiving flask (both solute and solvent captured)

Separate 2 or more liquids with different boiling points

/ HOMOGENEOUS (can use to remove impurities from water)
Chromatography
/ PHYSICAL / Separates particles based on:
1)size
2)solubility / HOMOGENEOUS

Check your Understanding:For each picture below:

a)Identify the separation technique from the list above.

b)Select the property that allows for the technique to work, from among these choices:

Differences in particle “attractiveness” or “electrical stickiness” of the mixture components, allowing them to be separated when solvent and some other medium (like paper) “compete” for the mixture components.

Differences in particle size of the mixture components.

Differences in particle boiling points of the mixture components.

Technique: ______

Property allowing it to work: # ___

Technique: ______Technique:______

Property allowing it to work: # ____Property allowing it to work: #____

Phases

Almost all substances can be made to change between the 3 phases, simply by altering the temp.

The classification of matter into solids, liquids and gases is termed as physical classification of matter.

Characteristics of solids

Solids maintain their volume independent of the size or shape of the container in which they are placed in.
Solids are rigid and have definite shape.
Solids diffuse very slowly compared to liquids and gases, due to close packing
Solids are incompressible.
Most solids melt on heating, and some sublimate.
Solids have very high mass to volume ratio or density compared to liquid or gases.
Solid molecules cannot move past one another.
Solids have strong Intermolecular forces of attraction.

Characteristics of liquids

Moderate forces of attraction exist between the molecules of a liquid.
The molecules in a liquid are in a state of random motion although the extent is much smaller in comparison to gases. The liquid molecules can flow past one another.
The average Kinetic energy of the molecules in a liquid is proportional to the temperature.

Characteristics of gases

Gases maintain neither volume nor shape and completely fill the container in which they are introduced.
Gases expand when heated.
Gases diffuse rapidly; we can smell perfume even when applied at a distance very fast.
Gases are highly compressible; if pressure is increased then volume decreases.
Almost all gases except a few are colorless.
Gases flow easily, moving past one another.
Gases have the weakest intermolecular forces of attraction.

Directions: Using the boxes provided below as your container, place six circular molecules in each container representing the given phase. Then on each line with the arrow label which phase change is occurring.

SOLID (s) LIQUID (l) GAS (g)

Practice

Fill in the table below.

Solid / Liquid / Gas
Shape
(Has a fixed shape or takes the shape of the container)
Volume
(Has a fixed volume or takes the volume of the container)
Density
(high or low)
Particle arrangement
(rigid or free)
Attraction
(particles are highly attracted and close or weakly attracted and spread out)

Heating Curve Worksheet

Below is a diagram showing a typical heating/cooling curve for water. It reveals a wealth of information about the structure and changes occurring in water as it is heated or cooled through all three phases of matter at different temperatures. At the top of the diagram are pictures representing the typical particle arrangement as substances change through their states.