Introduction: Measurement, Introduction: Measurement, Mathematical Operations; Mathematical Operations; Introduction to ChemistryIntroduction to Chemistry

Topic 1Topic 1

MeasurementMeasurementMeasurement, from the Greek word "metron", meaning limited proportion is the estimation of the magnitude of some attribute of an object, such as its length or weight, relative to a unit of measurement

Metrology is the scientific study of measurement

It involves using a measuring instrument, such as a ruler or scale, which is calibrated to compare the object to some standard, such as a meter or a kilogram

Units of MeasurementsUnits of MeasurementsImperial system

early used as English units then Imperial unitscame to known as US Customary Unitshave at times been called foot-pound-second systems

Metric Systema decimalised system of measurement based on the

metre and the gramit has a single base unit for each physical quantityall other units are powers of ten or multiples of ten of

this base unit

SI UnitsSystème International d'Unitésmodern, revised form of the metric systemtwo types of SI units, Base and Derived Units

SI Base UnitsSI Base UnitsNameName SymbolSymbol QuantityQuantity

metremetre mm LengthLength

KilogramKilogram kgkg massmass

secondsecond ss timetime

ampereampere AA electric currentelectric current

kelvinkelvin KK thermodynamic temperaturethermodynamic temperature

molemole molmol amount of substanceamount of substance

candelacandela cdcd luminous intensityluminous intensity

SI PrefixesSI Prefixesyotta,yotta, (Y),(Y), meaning 10meaning 102424 deci,deci, (d),(d), meaning 10meaning 10-1-1

zetta,zetta, (Z),(Z), meaning 10meaning 102121 centi,centi, (c),(c), meaning 10meaning 10-2-2

exa,exa, (E),(E), meaning 10meaning 101818 milli,milli, (m),(m), meaning 10meaning 10-3-3

peta,peta, (P),(P), meaning 10meaning 101515 micro,micro, (u),(u), meaning 10meaning 10-6-6

tera,tera, (T),(T), meaning 10meaning 101212 nano,nano, (n),(n), meaning 10meaning 10-9-9

giga,giga, (G),(G), meaning 10meaning 1099 pico,pico, (p),(p), meaning 10meaning 10-12-12

mega,mega, (M),(M), meaning 10meaning 1066 femto,femto, (f),(f), meaning 10meaning 10-15-15

kilo,kilo, (k),(k), meaning 10meaning 1033 atto,atto, (a),(a), meaning 10meaning 10-18-18

hecto,hecto, (h),(h), meaning 10meaning 1022 zepto,zepto, (z),(z), meaning 10meaning 10-21-21

deka,deka, (da),(da), meaning 10meaning 1011 yocto,yocto, (y),(y), meaning 10meaning 10-24-24

Instruments used for Instruments used for measuringmeasuring

ExampleExampleConvert the following measurements:Convert the following measurements:

1. 34 L = _____ cc1. 34 L = _____ cc2. 252. 25°F = _____ °K°F = _____ °K3. 2.0 mg = _____ kg 3. 2.0 mg = _____ kg 4. 3.5 hrs = ______ s4. 3.5 hrs = ______ s5. 1 x 105. 1 x 10-5-5 mol = ______ mol mol = ______ mol

ExampleExampleConvert the following measurements:Convert the following measurements:(Answer)(Answer)

1. 34 L = 1. 34 L = 34, 00034, 000cccc2. 252. 25°F = °F = 244.48244.48 °K °K3. 2.0 mg = 3. 2.0 mg = 0.00000200.0000020 kg kg 4. 3.5 hrs = 4. 3.5 hrs = 1260012600 s s5. 1 x 105. 1 x 10-5-5 mol = mol = 0.010.01 mmol mmol

Basic Mathematical Basic Mathematical OperationsOperationsMDASMDAS rule rule

Perform multiplication/division first Perform multiplication/division first before addition and subtractionbefore addition and subtraction

e.g.e.g.Solve the following:Solve the following:

1.1. 32(6+5) – 4/2 + (35+8)32(6+5) – 4/2 + (35+8)2.2. {3[4+8]/6} – (2+5(6)-12){3[4+8]/6} – (2+5(6)-12)

Basic Mathematical Basic Mathematical OperationsOperationsMDASMDAS rule rule

Perform multiplication/division first Perform multiplication/division first before addition and subtractionbefore addition and subtraction

e.g.e.g.Solve the following:Solve the following:

1.1. 32(6+5) – 4/2 + (35+8) = 32(6+5) – 4/2 + (35+8) = 3933932.2. {3[4+8]/6} – (2+5(6)-12) = -{3[4+8]/6} – (2+5(6)-12) = -1414

Rounding-off FiguresRounding-off FiguresRule 1: If the digit after that being retained is Rule 1: If the digit after that being retained is

LESS than 5,LESS than 5, the retained digit is the retained digit is unchanged. unchanged.

Rule 2: If the digit after that being retained is Rule 2: If the digit after that being retained is GREATER than 5,GREATER than 5, the retained digit is the retained digit is increased by one. increased by one.

Rule 3: f the digit after that being retained is Rule 3: f the digit after that being retained is EQUAL to 5,EQUAL to 5, what follows determines how what follows determines how to round the number. to round the number. If even number, retainedIf even number, retainedIf odd number, increase by 1If odd number, increase by 1

ExampleExampleRound to the nearest hundredths:Round to the nearest hundredths:

1. 2.3560 = _____ 1. 2.3560 = _____ 2. 2.3460 2. 2.3460 = _____= _____3. 2.3452 = _____ 3. 2.3452 = _____ 4. 2.3453 = _____4. 2.3453 = _____5. 2.3423 = _____5. 2.3423 = _____

ExampleExampleRound to the nearest hundredths:Round to the nearest hundredths:(Answer)(Answer)

1. 2.3560 = 1. 2.3560 = 2.362.36 2. 2.3460 2. 2.3460 = = 2.352.353. 2.3452 = 3. 2.3452 = 2.342.344. 2.3453 = 4. 2.3453 = 2.352.355. 2.3423 = 5. 2.3423 = 2.342.34

Significant FiguresSignificant FiguresGuidelines for Using Significant FiguresGuidelines for Using Significant Figures1.1. Any digit that is not zero is significant.Any digit that is not zero is significant.2.2. Zeros between nonzero digits are significant.Zeros between nonzero digits are significant.3.3. Zeros to the left of nonzero digit are not significant.Zeros to the left of nonzero digit are not significant.4.4. If a number is greater than 1, all zeros written after the decimal If a number is greater than 1, all zeros written after the decimal

point is significant.point is significant.5.5. If a number is less than 1, zeros before the nonzero digit is not If a number is less than 1, zeros before the nonzero digit is not

significant.significant.6.6. For numbers that do not contain decimal point, the trailing zeros For numbers that do not contain decimal point, the trailing zeros

(zero after the nonzero digit) may or may not be significant.(zero after the nonzero digit) may or may not be significant.7.7. In addition and subtraction, the number of significant figures in In addition and subtraction, the number of significant figures in

the answer is determined by the digit that has the least number the answer is determined by the digit that has the least number of decimal places.of decimal places.

8.8. In multiplication and division, the number of significant figures in In multiplication and division, the number of significant figures in the product or quotient is determined by the original number the product or quotient is determined by the original number that has the least number of significant figures.that has the least number of significant figures.

Significant FiguresSignificant FiguresExample:Example:

1.1. 5.015.012.2. 0.021200.021203.3. 7,1007,1004.4. 7.10 x 107.10 x 1033

5.5. 2.4562.456

Significant FiguresSignificant FiguresExample:Example:

1.1. 5.01 = 5.01 = 332.2. 0.02120 = 0.02120 = 443.3. 7,100 = 7,100 = 224.4. 7.10 x 107.10 x 1033 = = 335.5. 2.456 = 2.456 = 44

Significant FiguresSignificant FiguresExample:Example:

1.1. 12,524.1 + 0.119312,524.1 + 0.11932.2. 8.60 x 2.13358.60 x 2.13353.3. 0.0154 / 1.30.0154 / 1.3

Significant FiguresSignificant FiguresExample:Example:

1.1. 12,524.1 + 0.1193 = 12,524.1 + 0.1193 = 12524.212524.22.2. 8.60 x 2.1335 = 8.60 x 2.1335 = 18.318.33.3. 0.0154 / 1.3 = 0.0154 / 1.3 = 1.2 x 101.2 x 10-2-2

Scientific NotationScientific NotationIn observance of significant figures, In observance of significant figures,

scientist used scientific notation to scientist used scientific notation to express extremely large or small express extremely large or small numerical values. All can be numerical values. All can be expressed in the form:expressed in the form:

N x 10N x 10nn

Step 1: Find nStep 1: Find n

Step2: Count the number of places that Step2: Count the number of places that the decimal point must be moved to give the decimal point must be moved to give the number N.the number N.

Step 3: If the decimal point has to be Step 3: If the decimal point has to be moved to the moved to the leftleft, n is a positive integer , n is a positive integer or to the or to the rightright, n is a negative integer , n is a negative integer

Scientific NotationScientific Notation

Example:Example:

1.1. 568213.5568213.52.2. 18162.0718162.073.3. 0.0000920.000092

Scientific NotationScientific Notation

Example:Example:

1.1. 568213.5 = 568213.5 = 5.682135 x 105.682135 x 1055

2.2. 18162.07 = 18162.07 = 1.816207 x 101.816207 x 1044

3.3. 0.000092 = 0.000092 = 9.2 x 109.2 x 10-5-5

Scientific NotationScientific Notation

Accuracy and PrecisionAccuracy and PrecisionAccuracy Accuracy determines how close a determines how close a

measurement is to the true value of measurement is to the true value of the quantity that is being measured.the quantity that is being measured.

PrecisionPrecision refers to the closeness of two refers to the closeness of two or more measurements of the same or more measurements of the same quantity with one another. quantity with one another.

ErrorErrorErrorError refers to a difference between refers to a difference between

actual behavior or measurement and actual behavior or measurement and the norms or expectations for the the norms or expectations for the behavior or measurementbehavior or measurement

Two types:Two types:1. Systematic Error (determinate)1. Systematic Error (determinate)2. Random Error (indeterminate) 2. Random Error (indeterminate)

ErrorError

ChemistryChemistryHistoryHistory

began with the discovery of firebegan with the discovery of fire

leads to the purification of metalsleads to the purification of metals(metallurgy)(metallurgy)

alchemyalchemy

AlchemyAlchemyMission:Mission:

protoscienceprotoscience

to discover the elixir to discover the elixir of life of life (fountain of youth)(fountain of youth)

to create gold through to create gold through transformationtransformation

AlchemyAlchemyFailure:Failure:

no scientific methodno scientific methodunable to established nomenclatureunable to established nomenclatureunable to reproduce experimentsunable to reproduce experiments

TimelineTimelineFirst chemists – the MoslemsFirst chemists – the MoslemsGeber – the father of chemistryGeber – the father of chemistry

Robert Boyle – alchemist turned chemistRobert Boyle – alchemist turned chemistdifferentiate alchemy and chemistrydifferentiate alchemy and chemistry

Antoine Lavoisier Antoine Lavoisier

TimelineTimelineAristotleAristotle““atomos”atomos”

John DaltonJohn Dalton

J. J. ThomsonJ. J. Thomson

Ernest RutherfordErnest Rutherford

TimelineTimelineChadwickChadwick

Niels BohrNiels Bohr

E. SchrodingerE. Schrodinger

Dmitriv MendeleyeevDmitriv Mendeleyeev

Inorganic chemistry is the study of the properties and reactions of inorganic compounds.

Organic chemistry is the study of the structure, properties, composition, mechanisms, and reactions of organic compounds. In other words, it is the study of those substances that contain carbon.

Divisions of Chemistry Divisions of Chemistry

Divisions of Chemistry Divisions of Chemistry Analytical chemistry is the analysis of material samples

to gain an understanding of their chemical composition and structure. Analytical chemistry incorporates standardized experimental methods in chemistry.

Biochemistry is the study of the chemicals, chemical reactions and chemical interactions that take place in living organisms.

Physical chemistry is the study of the physical basis of chemical systems and processes. In particular, the energetics and dynamics of such systems and processes are of interest to physical chemists.

Other subdivisions:Other subdivisions:

Astrochemistry Atmospheric chemistryChemical Engineering Chemo-informatics

Electrochemistry Environmental chemistry Geochemistry Green chemistryHistory of chemistry Materials scienceMedicinal chemistry Molecular Biology

Molecular genetics Nanotechnology Organometallic chemistry PetrochemistryPharmacology PhotochemistryPhytochemistry Polymer chemistry

Supramolecular chemistry Surface chemistry Thermochemistry Theoretical Chemistry

Nuclear Chemistry

Divisions of Chemistry Divisions of Chemistry