Chemistry Survival Guide

transcript

A Visual Guide to Understanding Chemistry

Intro to Chemistry

Atomic Structure

Periodic Table

Compounds

Quantitative Chemistry

Gas Laws

Nuclear Chemistry

Thermochemistry

Solutions

Acids & Bases

“Chemistry in the Real World”

The science community* has increasingly identified the content focus and the instructional practices as the two areas most in need of change (McCleery & Tindal, 1999).

*(National Science Teachers Association, the American Association for the Advancement of Science, and the National Science Foundation Education Association)

Focusing the Content

Sequencing Activities

Minimizing Learner Demands

Teaching in Small Steps

Guiding Students During Initial Practice

Providing High Levels of Successful Practice

Flexible Curricula

Multiple Representations of Presented Information

Multiple Means of Expression and Control

Multiple Means of Motivating and Engaging Students

(Orkwis, 1999)

Intensified:

Theme-Based:

Hands-On

Long Term Activities

Interrelationships Among Unifying Processes

(Cawley, Foley, & Miller, 2003)

Classifying Matter

Accuracy & Precision

Calculating Percent Error

Metric System & Unit Conversion

Scientific Notation

Physical vs. Chemical Properties

Pure Substances Mixtures & Compounds

Calculating Density

Matter

Substance Mixture

Element Compound Hetero geneous

Homo geneous

MatterAnything with Mass & Volume

SubstanceMatter with a constant composition, wherever it is found

Mixture

Matter with variable composition that is physically combined

ElementMade up of only one atom

CompoundTwo or more elements chemically combined

HeterogeneousMade up of more than one phase

HomogeneousMade up of only one phase, considered uniform

DENSITY: A physical property of matter, measured in: grams, or g/ml or g/cm3

D = M/V Density = Mass divided by Volume (g or g/ml or g/cm3)

M = D V Mass = Density times Volume (in grams)

V = M/D Volume = Mass divided by Density ( in ml, l,

V = LWH Volume = Length times Width times Height

Density = Mass / Volume

Mass = Density x Volume

Volume = Mass / Density

G MG X 1000

G CG X 100

MG G X 1/100

CG G X 1/100

L ML X 1000

M L 1000

M KM 1000

KM M X 1000

PREFIX DECIMAL EQUIVALENT

EXPONENTIAL EQUIVALENT

Pico 0.000000000001 10-12

Nano 0.000000001 10-9

Micro 0.000001 10-6

Milli 0.001 10-3

Centi 0.01 10-2

Deci 0.1 10-1

Kilo 1000.0 10 3

Mega 1,000,000. 10 6

Giga 1,000,000,000.0 10 9

10+ 10

Move Decimal point # of times to left

Move Decimal point # of times to right

6028 L = 6.028 x 103 L 0.006L = 6 x 10 -3 L

PHYSICAL CHEMICAL

Can be measured w/o changing the chemical nature of the substance from one state to another

Can be observed when matter is altered, and undergoes a irreversible change

Mass, Volume, Density, Area, Length, Emission of Light, Absorption of Heat/Cold, Melting & Boiling point, Color

Evolution of a Gas (fizzles, bubbles) Forming a Precipitate (solid)

Aluminum foil is cut in half. Milk goes sour.

Clay is molded into a new shape. Jewelry tarnishes.

Butter melts on warm toast. Bread becomes toast.

Water evaporates from the surface of the ocean.

Rust forms on a nail left outside.

A juice box in the freezer freezes. Gasoline is ignited.

Rubbing alcohol evaporates on your hand.

Hydrogen peroxide bubbles in a cut.

Ice melting Food scraps are turned into compost in a compost pile.

A Diamond cutting glass A match is lit.

You take an antacid to settle your stomach.

Your body digests food.

You fry an egg

Pure Substances Mixtures Compounds

Can be element or compoundContains only one type of

substance

Can be element or compound

Combinations of other pure substances

Contain two or more elements bonded together chemically. The chemical formula contains two or more capital letters

Has fixed definite composition No Definite ratio ALWAYS a definite ratio

Can be separated physically Can ONLY be separated chemically

A physical blend

Atomic Structure

Atomic Scientists

Orbital Filling Diagram

Atoms are indestructible, indivisible, and identical.

Combine in simple ratios called the Law of Definite Proportions.

Atoms are not created or destroyed during a reaction.

Cathode Ray tube experiment

Plum Pudding model

Opposite charged particles (electrons) attract

Alpha Particles and Gold Foil experiment

Atoms are mostly “empty space”

Nucleus is small but has almost all of atom’s mass

Planetary model

Electrons occupy specific orbits around the nucleus

Particle Charge Mass Location

Proton + 1 Nucleus

Electron - 0 Orbital/Ring/cloud

Neutron No Charge 1 Nucleus

1S22S22P4

ALUMINUM Z=13 1S2 2S2 2P6 3S2 3P1

Protons, Electrons & Neutrons

Periodic Table of the Elements

Periods & Groups

Blocks

Trends

Atomic Number = Number of Protons

Number of Protons = Number of Electrons

Mass Number – Atomic Number = Number of Neutrons

# of P’s = # of E’s

Mass # - Atomic # = # of N’s

Arranged vertically in GROUPS

Arranged horizontally in PERIODS

Arranged in BLOCKS (S, D, P, F)

Atomic Radius &

Metallic Character

Ionization Energy

Electronegativity

INCREASES DOWN A GROUP

DECREASES ACROSS A PERIOD INCREASES ACROSS A PERIOD DECREASES DOWN A GROUP

Group 1

Group 2

Group 13

Group 15

Group 16

Group 17

Binary Ionic Compounds

Bonding

Writing Formulas

Lewis Dot Structures

IONIC COMPOUNDS:

NAMING BINARY IONIC COMPOUNDS:

Any chemical compound that is composed of oppositely charged ions

The name of the CATION followed by The name of the ANION + IDE

NAMING BINARY COMPOUNDS OF TWO NONMETALS (Given formula, write name)

Do Not use the prefix “mono” for the 1st elementUse the prefixes (1-10) and end in IDE

N2O = Dinitrogen Monoxide NO2 = Nitrogen Dioxide

NUMBER PREFIX

ONE MONO

TWO DI

THREE TRI

FOUR TETRA

FIVE PENTA

SIX HEXA

SEVEN HEPTA

EIGHT OCTA

NINE NONA

TEN DECA

BONDING

IONIC MOLECULAR COVALENT BOND

Metal & Non-Metal Non – Metal & Non-Metal

1, Name the 1st element 1. Do not use Roman Numerals2. Make the 2nd element = IDE 2. Use Prefixes ( Mono, Di, Tri)3. Use Roman Numerals ( I, II, III) 3. 2nd element ALWAYS has if Transition Element (3-12) PREFIX & IDE4. Reduce to lowest terms 4. Do Not Reduce

METALLIC COVALENT IONIC

WEAKEST STRONGER STRONGER

GOOD CONDUCTOR AS SOLID OR

SOLUTION

POOR CONDUCTOR ASSOLID OR SOLUTION

POOR CONDUCTORS AS

SOLID GOOD AS SOLUTION

MALLEABLE DUCTILE BRITTLE HARD BRITTLE

LOW MELTING POINT HIGH MELTING POINT HIGH MELTING POINT

LOW BOILING POINT HIGH BOILING POINT HIGH BOILING POINT

“SEA OF ELECTRONS”

Sodium Nitride

Formulas are created by the “CROSS-OVER” Method

Sodium Nitride =

Sodium (Na) & Nitrogen (N)

Transition Metals Groups (3-12) & The Ions They Form

Iron = Fe3+CationCation

Chlorine = Cl -AnionAnion

Fe 3 Cl -+

Iron (III) Chloride = Fe Cl3

F -Lead (Pb) & Flourine (F)

Lead (II) Fluoride = Pb F2

NUMBER ROMAN NUMERAL

TWO II

THREE III

FOUR IV

FIVE V

SIX VI

SEVEN VII

EIGHT VIII

NINE IX

Obey the Octet Rule 8 electrons in the valence shell is stable

Hydrogen has 1 valence electron

Oxygen has 6 valence electrons

Hydrogen has 1 valence electron

HH22OO

Dihydrogen Monoxide =

Moles & the Mole Concept

Stoichiometry

Percent (%) Composition

Molecular & Empirical Formulas

Balancing Chemical Equations

Types of Reactions

Moles & #’s of Particles

Atoms Particles Molecules

Multiply by 6.02 x 1023

Divide by 6.02 x 1023

Moles & Grams

Moles Grams

Multiply by Molar Mass*

Divide by Molar Mass

* From Atomic Mass on Periodic Table

Moles # of Particles, Atoms, Molecules

Use Avogadro’s # 6.02 x 1023

Moles Grams

Use Molar Mass from Periodic Table

General Plan for Converting

Mass, Amount & # of Particles

Using Equations to make a recipe for a Ham & Cheese Sandwich

2 slices Bread + 2 slices Ham + 1 slice cheese + 1 leaf Lettuce =

1 Ham & Cheese Sandwich

A ratio of : 2 : 2 : 1 : 1 Balanced Equation

In order to feed 20 people Ham & Cheese Sandwiches you need ?

40 slices Bread 40 slices Ham 20 slices Cheese 20 leaves Lettuce

2Bd (s) + 2Hm (s) + 1Ch (s) + 1Lt (s) Bd2 Hm2ChLt (s)

Bread + Ham + Cheese + Lettuce Sandwich

Reactants Product

Making a sandwich is analogous to a chemical reaction

A “Recipe” that calls for: a ratio of specific ingredients

Molar Mass of Element

Total Molar Mass

X 100 = %%

HH22OOMass of H2 = 2 + Mass of O = 16 …….. Total Molar Mass = 18

2/18 = .111 x 100 = 11.1 % H11.1 % H

16/18 = .888 x 100 = 88.8 % O88.8 % O

Empirical Molecular

Cannot Be Reduced

CanBe Reduced

Na2 SO3 S2Cl2

REACTANTS PRODUCTS

C3H4 O2 CO2 H2O+

C3H4 O2+ 4444 CO2 H2O33

A + B C = Combination/Synthesis

A +O2 AO = Combustion

A CO2 +H2O = Decomposition

A +BC AC +B = Single Replacement

AB +CD AD +BC = Double Replacement

Extinguishes Flame

Causes Explosion

Reignites Flame

Nuclear Particles

Types of Decay

Radioactive Half-Life

Name Symbol in Equations

Greek Symbol

Penetration Power

Alpha Particle + 4

α Stopped by skin or a piece of paper

Beta Particle (electron)

β- Stopped by a few sheets of aluminum foil

Gamma Radiation

γ Stopped by several centimeters of lead

Neutron 1 0

Stopped by a few centimeters of lead

Positron (electron’s

antiparticle)

β+ Stopped by a few sheets of aluminum foil

Alpha Decay

He= = Sum of the Mass # = Sum of the Mass #

Beta Decay

-1e = On right side, increase Atomic # by 1

Mass # remains the same

Electron Capture

On left side, Mass # is same Atomic # decreases by 1

Positron Emission

e == On right side, Mass # is same Atomic # decreases by 1

Types of Decay

Site of Reaction

Particle When it Happens

What Happens

Alpha Right + 4+ 2

Too Many Neutrons

Mass # - 4Atomic # - 2

Beta Right 0-1

Too ManyNeutrons

Atomic # + 1

PositronEmission

Right 0+1

Too Few Neutrons

Atomic # - 1

ElectronCapture

Left 0-1

Too Few Neutrons

Atomic # - 1

One Half Life

Two Half Lives

Three Half Lives

Four Half Lives

50% or 1/2

25% or 1/4

12.5% or 1/8 6.25% or 1/16

Half–Life = Amount of time it takes for ½ of material to decay

Half–Life is a constant value unaffected by external conditions

Standard Conditions

Pressure Conversions

Gas Laws

Boyle’s Law

Charles’s Law

Gay-Lussac’s Law

Combined Gas Law

Ideal Gas Law

TemperatureTemperature

0.00 0CCelsius

273 KKelvin

O + 273=Kelvin

PressurePressure

1.00 atm

760 mmHg

101.325 kPa

101,325 Pa

kPa101.325

atm1.00

mmHg760

X 101.325 X 760

÷ 101.325 ÷ 760

Boyle’s Law = P1 × V1 = P2 × V2 (PV = K)(Inverse)

Charles’s Law = V1 V2

= (V K )T

(Direct)

Gay-Lussac’s Law (Direct)

= (P K )T

Avogadro’s Law

= (V/n = K)

Dalton’s Law Partial Pressure

= P1 + P2 + P3 + Pn = P Total

When Pressure increases P

Then Volume decreases V

P1 =P2 V2

V1V1 =

V2 =P1V1

P2P2 =

When Volume Increases V

Then Temperature Increases T

V1 =V2 T1

T2V2 =

T2 =V2 T1

V1T1 =

When Pressure Increases P

Then Temperature Increases T

P1 =P2 T1

T2P2 =

T2 =P2 T1

P1T1 =

P1 V1=

Peas (P) & Vegetables (V) on the Table (T)

PV = nRT

P = the pressure of a sample of gas

V = the volume of a sample of gas

n = the number of moles of a gas present

T = the Kelvin temperature of the gas

R = the ideal gas constant, which combinesstandard conditions & molar volume into a single constant

Thermochemistry

Thermochemical Formulas

Phase Changes

Energy

Thermochemical Equations

The amount of heat energy to raise temperature

( a quantity of energy ) = “ Joules”

q = Specific Heat Capacity in joules

m = Mass in grams or moles

∆T = Change in temperature

If the problem involves mass (m) then use specific heat capacity. If the problem involves the # of moles (n) then use the molar heat capacity

q = Cp (m) (∆T)

q = Cp (n) (∆T)or

Cp (∆T)=

Cp (m)(∆T)

FusionFreezing

Condensation

Vaporization

All forms of energy can be divided into two categories

Kinetic Energy (KE) = Energy of Motion

Potential Energy (PE) =Result of the Attractions & Repulsion between objects

KE Energy in Action Energy of Motion

PE Stored Energy Energy of Position

Fusion

PE + KE =

Vaporization

KE +PE + KE =

EXOTHERMIC REACTIONS ENDOTHERMIC REACTIONS

Heat is released Heat is absorbed

Enthalpy ( heat ) of the products is less than that of the reactants

Enthalpy (heat) of the products is greater thanthat of the reactants

H= Hprod. – Hreactant H 0 (negative)

H= Hprod. – Hreactant H 0 (positive)

Favorable reaction – nature prefers lower energy

Unfavorable reaction

Products are more stable Reactants are more stable

Energy term is on products side of equationC(s)+ 02 (g) CO2(g) + 393.5 kJ

A + B C + HEAT

Energy term is on the reactants side of equationN2(g) + 2 02(g) + 66.2 kJ 2 NO2 (g)

X + Y + HEAT Z

Reactants

ProductsFinal enthalpy

Initial enthalpy

Heat absorbed∆ H

(positive)

Reactants

ProductsFinal enthalpy

Initial enthalpy

∆ H (negative)

Heat Released (lost)

Solutions

Concentration

Molarity

Dilution

SolutionsSolutions

Homogeneous mixtures that are made up of only one phase and are physically combined

Unsaturated Unsaturated A solution that can still dissolve more solute

SolventSolvent

The part of the solution

that gets dissolved

SoluteSolute

The part of the solution that

does the dissolving

SaturatedSaturated….has reached max. amount of solute

SupersaturatedSupersaturated....holds > than max.amount of solute

(M) Molarity =# of moles of solute

# of liters of solutionor

Liters

# of Liters =mol

# of moles = (M) ( # of Liters)

Mass of a Solute = M x L = mol x molar mass = Mass in (g)

Divide by # of grams from Molar Mass on Periodic Table

Divide by 1000 to convert ML to L

moles grams

ML Liters

(x) Multiply by molar mass

(÷) Divide by molar mass

# of ml (÷) 1000

# of ml (x) 1000

M = Molarity V = VolumeMolarity1 x Volume1 = moles solute = Molarity2 x Volume2

M1 x V1 = M2 x V2

M1 =M2V2

M2 =M1V1

V1 =M2V2

V2 =M1V1

Naming Acids & Bases

Titration

Using Polyatomic Ions & convert the suffix*

ATE IC = H2SO4 = Sulfuric Acid

ITE Ous =H2SO3 = Sulfurous Acid

ACIDS ACIDS BASESBASESBEGIN W/ A HYDROGEN ATOM

H2SHydrosulfuric Acid

END IN (OH)KOH

Potassium Hydroxide

TASTE SOUR TASTE BITTER

TURN LITMUS PAPER “RED” TURN LITMUS PAPER “BLUE”

DESTROY CHEMICAL PROPERTIES OF BASES

DESTROY CHEMICAL PROPERTIES OF ACIDS

pH of H (ACID) < 7 pH of OH (BASE) >7

pH = Negative logarithm of the hydrogen ion concentration

pH = -LOG(H+)

Concentration of Acid (H+) = Concentration of Base (OH)

MA x VA = MB x VBMA = Molarity of the Acid

VA = Volume of the Acid

MB = Molarity of the Base

VB = Volume of the Base

MA =MBVB

MB =MAVA

VA =MBVB

VB =MAVA

Cosmetics

Chemical Warfare

Forensic Science

Food Additives & Preservatives

Global Warming

Heavy Metal Poisons

Cawley, J.F., Foley, T.E., & Miller, J. (2003) Science and Students with Mild Disabilities: Principles of Universal Design. Intervention in School and Clinic, 38, 3, 160-171.

Holt ChemFile. Mini-Guide to Problem Solving.Holt, Rinehart and Winston. Austin: Texas.

Mascetta, J.A., (1996) Chemistry the Easy Way. Barrons Educational Services. Hauppauge:New York

McCleery, J.A., & Tindal G.A. (1999) Teaching the Scientific Method to At-Risk Students and Students with Learning Disabilities Through

Concept Anchoring and Explicit Instruction. Remedial And Special Education, 20, 1, 7-18.

Orkwis, R. (1999) Curriculum Access and Universal Design, Reston,VA: Council for Exceptional Children

Chemistry Survival Guide

Documents