HONORS CHEMISTRYUnit A: Matter and Measurements

CHAPTER ONE: MATTER AND CHANGE

WHAT IS CHEMISTRY?uCHEMISTRY is the study of the composition,

structure, and properties of matter, the process that matter undergoes, and the energy changes that accompany these processes.

WHAT IS MATTER?uMATTER is anything that has mass and

volume – no matter how small the measurement.

uMASS is a measure of the amount of matter

uVOLUME is a measure of the space taken up by matter

WHAT IS AN ATOM?uATOMS are the smallest unit of an element

that maintains the chemical identity of that element

WHAT IS AN ELEMENT?uELEMENTS are pure substances that cannot

be broken down into simpler, stable substances and are made of only a single kind of atom.

WHAT IS A COMPOUND?uCOMPOUNDS are substances that can be

broken down into simple stable substances. Compounds are made from two or more elements that are chemically bonded

PROPERTIES OF MATTERuPROPERTIES of matter help to define and

classify substances. They can reveal the identify of an unknown substance.

uEXTENSIVE PROPERTIES depend on the amount of matter presentuEx. MASS, VOLUME, ENERGY

uINTENSIVE PROPERTIES do not depend on the amount of matter presentuEx. DENSITY, m.p., b.p., CONDUCTIVITY

PHYSICAL PROPERTIESuPHYSICAL PROPERTIES of matter can be

observed w/o changing the identity of the substance.

uPHYSICAL CHANGE doesn’t change the identity of the substanceuEx. Cutting, Grinding, Phase Changes

CHEMICAL PROPERTIESuCHEMICAL PROPERTIES of matter relate to a

substance’s ability to undergo change to form a new substance.

uCHEMICAL CHANGE results in a substance(s) being converted to a new substance(s)uEx. Combustion, Oxidation, Decomposition

CHEMICAL REACTIONuCHEMICAL REACTION is a process that involves

a chemical changeuReactants change to form new Products

CONSERVATION OF ENERGY & MATTER

uIn a chemical reaction matter is neither created nor destroyed. It can be accounted for and converted.

uIn a chemical reaction energy can be absorbed (endothermic) or released (exothermic), but not created or destroyed.

CLASSIFICATION OF MATTER

uMatter exists in a variety of forms and divided into two major types: Mixtures & Pure Substances

MIXTURESuMIXTURES are a blend of two or more kinds of

matter. Each substance retains its own properties.

MIXTURE GROUPSuHOMOGENEOUS MIXTURES are uniform and

appear as a single substance. Homogeneous mixtures are also called solutions

uHETEROGENEOUS MIXTURES are non-uniformuMixtures can often be physically separated by

filtration, vaporization, or other lab techniques.

PURE SUBSTANCESuPURE SUBSTANCES have a fixed composition for

all samples. They are either Elements or Compounds.

The Periodic Table of the Elements

uElements are organized on The Periodic TableuOver 100 elements are knownuElements are organized into Groups/Families

and Periods.uElements are also classified as Metals,

Nonmetals, and Metalloids.

Types of ElementsuMETALS are good conductors, malleable, and

are ductile and have luster. (Cu)uNONMETALS are poor conductors, brittle, and

usually gases at room temperature. (Ne)uMETALLOIDS are a small group of elements that

share characteristics with metals and nonmetals. (Si)

HONORS CHEMISTRYUnit A: Matter and MeasurementsCHAPTER TWO: MEASUREMENTS & CALCULATIONS

SI MeasurementuSI is the universal measurement system used

by scientistsuMEASUREMENTS represent quantities

(descriptive amounts)uQUANTITY is something that has magnitude,

size, or amount (numerical value)

SI BASESuThere are 7 SI bases and many derived or

combination unitsuThe “Big 5” are LENGTH, MASS, TIME,

TEMPERATURE, and AMOUNT OF SUBSTSANCE

MASSuSI Unit: Kilogram (kg)u1 kg = 1,000 g = 1,000,000 mguMASS is not the same as WEIGHTuWEIGHT is a force dependent upon gravity

LENGTHuSI Unit: Meter (m)u1 km = 1,000 m = 1,000,000 mm

AMOUNT (of a substance)uSI Unit: Mole (mol)u1 mole = 6.02 x 1023

uThe MOLE is a really large number that is useful when quantifying really small things like atoms

TEMPERATUREuSI Unit: Kelvin (K)uThe KELVIN scale has no negative values and

has incremental change equal to the CELCIUS scale

u△1◦C = △1Ku0 K = -273 ◦CuK à ◦C (subtract 273)u◦C à K (add 273)

VOLUMEuSI Unit: Meter (m3)uVOLUME is a derived unit – length in 3DuVOLUME units are often expressed as:

uLiters (L), Mililiters (mL), Cubic Centimeters (cm3)u1 L = 1,000 mL = 1,000 cm3

DENSITYuDENSITY is the ratio of mass per unit volumeuDENSITY = D = M/VuDENSITY units are often expressed as:

uKilograms per cubic meter (kg/m3)uGrams per cubic milliliter (g/mL)

CONVERSION FACTORSuA ratio derived from an equality between two

different unitsuUsed to convert one unit to anotheruFormatted as FRACTIONS

uDesired “New” unit on TOPuStarting “Old” unit on BOTTOM

DIMENSIONAL ANALYSISuMath technique that uses conversion factors to

solve problems with units of measureuMultiplication & Fractions!

uExamples on the board: uTime, Mass, Moles

ACCURACY & PRECISIONuACCURACY refers to the closeness of a

measurement to the correct or accepted valueuPRECISION refers to the closeness of a set of

measurements of the same quantity

PERCENT ERRORu% ERROR compares the accuracy of an

experimental value with an accepted valueuKind of like “grade” for your experimental

measurements or data uValues closer to 0% are best

Measurement ErroruNo measurements are “perfect”uErrors in measurement are due to human and

instrumental limitationsuEstimation is involved in the final questionable digit of

a measurementuExamples: 2.5 days vs. 2 days, 12 hours, 1.5 minutesuSun vs. Clock

Sig FigsuSIGNIFICANT FIGURES in a measurement consist of all

the digits known with certainty plus one final digit, which is estimated or uncertain

Sig Fig OperationsuADDITION & SUBTRACTION: the answer must have the

same number of digits to the right of the decimal point as there are in the measurement with the fewest digits to the right of the decimal point

Sig Fig OperationsuMULTIPLICATION & DIVISION: the answer can only

have as many significant figures as the measurement with the fewest sig figs

Scientific NotationuSCIENTIFIC NOTATION expresses quantities with non-

significant zeros in a compact formuM x 10n (Avogadro’s # 6.02x1023)u The “M” value must be greater than or equal to 1

and less than 10

Scientific Notation Rules

ProportionalityuDIRECTLY PROPORTIONAL: the quotient of the two

variables is constant (y/x = constant)uTemperature & Volume

u INVERSELY PROPORTIONAL: the product of the two variables is constant (xy = constant)uPressure & Volume