CHAPTER ONEThe Foundations of Chemistry

RECALL!!!

Elements: Can not be broken down by chemical reactions

Pure Substances Compounds: Can be broken down

ONLY by chemical reactions

Matter Homogeneous: Constant

composition throughout

Mixtures Can be separated by Heterogeneous: Variable

composition physical processesthroughout 2

3

States of Matter

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A

B C

D

E

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States of Matter

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Chemical and Physical Properties Chemical Properties - chemical

changes rusting or oxidation chemical reactions

Physical Properties - physical changes changes of state density, color, solubility

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Question 1. Classify as mixtures (homogeneous or heterogeneous), compounds (ionic or molecular), or elements (monoatomic or molecular).Classification

C2H5OH

Cl2Cu

bronze

5% AgNO3 solution

C6H12O6

PbCl2 precipitate

Zn

Ba3(PO4)2

0.5 M CaCl2

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Mixtures, Substances, Compounds, and Elements

Separation of Mixtures Distillation: It separates 2 or more liquids with different boiling points. For example: ethanol (bp: 78°C) and water (bp: 100°C) Fractional crystallization: It separates 2 or more solids (by means of precipitation) with different solubility. Filtration: It separates an insoluble solid from a liquid. The solid must be insoluble in the liquid. For example: sand-water, silver chloride-water. Chromatography: It separates substances that are soluble in a solvent by means of IMF. Evaporation: It separates a soluble solute from its solvent by evaporating the solvent. For example: NaCl-H2O Liquid – liquid separation: It separates 2 immiscible liquids using a separatory funnel. For example: oil-water

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Distillation

Separates homogeneous mixture on the basis of differences in boiling point.

Ethanol-water

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FiltrationSeparates insoluble solid substances from liquids and solutions.

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Chromatography:Separates substances on the basis of differences in solubility in a solvent and IMF.

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Measurements in Chemistry

Quantity UnitSymbol

length meter m

mass kilogram kg

time second s current ampere A temperature Kelvin K amt. substance mole

mol

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Measurements in ChemistryMetric PrefixesName Symbol Multiplier

mega M 106 kilo k 103 deci d 10-1 centi c 10-2 milli m 10-3 micro μ 10-6 nano n 10-9 pico p 10-12 femto f 10-15

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Units of Measurement

Common Conversion Factors Length

2.54 cm = 1 inch Volume

1 liter = 1.06 qt Mass

1 lb = 454 g

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Volume The most commonly

used metric units for volume are the liter (L) and the milliliter (mL). 1 dm = 10 cm 1 dm3 = 1000 cm3

1 L = 1000 mLtherefore 1 mL = 1 cm3

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Uncertainty in Measurements

Different measuring devices have different uses and different degrees of accuracy.

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Relationships of the Temperature Scales

Kelvin and Celsius RelationshipK = °C + 273.15

Fahrenheit and Celsius Relationship°F = 1.8 * °C + 32

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Use of Numbers

Exact numbers 1 dozen = 12 things for example

Accuracy how closely measured values agree with the correct

value. The experimental value is 23.5148g, the actual value is 23.5150g. These 2 masses are accurate.

Precision how closely individual measurements agree with

each other. The value of the mass of the same beaker in 3 trials are: 23.5148g, 23.5152g, 23.5145g. These values are precise.

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Percent error Percent error = accepted – experimental x

100 accepted

From previous example:% error = 23.5150 – 23.5148 x 100 = 0.0009 % 23.5150

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Use of Numbers

Significant Figures – Rules All non-zero digits are significant. Leading zeroes are never significant

0.000357 has three significant figures Imbedded zeroes are always significant.

2.0059 has five sig fig Trailing zeroes are only significant after the

decimal point. 1300 g has 2 sig fig 13.00 g has 4 sig fig

Use scientific notation to remove doubt1.300 x 103 has 4 significant figures

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Use of Numbers

Multiplication & Division rule Easier of the two rulesProduct has the smallest number of

significant figures of multipliers

5.22 tooff round

21766.5

31.2x

224.4

3.9 tooff round

89648.3

41.x

2783.2

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Use of Numbers

Addition & Subtraction ruleMore subtle than the multiplication ruleAnswer contains smallest decimal place of the

addends.

6.95 tooff round

9463.6

20.2

423.1

3692.3

6.671 tooff round

6707.6

312.2

7793.8

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Use of Numbers

On a multi-step question, solve all mathematical steps and ONLY round off the final answer.

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Using Factor Label Method

Example: A concentrated hydrochloric acid solution is 36.31% HCl by mass. The density of the solution is 1.185g/mL. What mass of pure HCl is contained in 175 mL of this solution?

solution g 100.00

OH g 63.69or

solution g 100.00

HCl g 36.31or

OH g 63.69

HCl g 36.31

Problem thisfrom Factors UnitPossible Some

2

2

mL

g 1.185density

HCl g 75.3

soln g 100.00

HCl g 36.31

soln mL 1

soln g 1.185soln mL 175

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Problem 2. Calculate the volume of solution required to prepare 0.025 M solution of Na2SO4 if only 0.050g of the salt is available. Known:

Molar mass of Na2SO4 is 142.1 g/mol. 0.025 M means 0.025 mol/L.

Problem 3. Calculate the density of a cobalt(II) chloride solution with a molarity of 3.57 M and a percent mass by mass of 17.46%.

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Review Nomenclature Compounds: Ionic Covalent Hydrates Acids

Ionic compounds

Metal + Nonmetal

Groups IA, IIA,Al, Ag, Zn, Cd

Only one oxidation number

Name of the metaldoes not change:lithium, calcium

Other metals

More than oneoxidation number

Roman numerals to specify charge:iron(II), iron(III),tin(II), tin(IV)

Stem of element + ideoxide, sulfide, chloride

BinaryTwo elements Ternary

More than two elements

Ionic compounds

Metal or NH4+ + Polyatomic anion

Groups IA, IIA,Al, Ag, Zn, Cd

Only one oxidation number

Name of the metaldoes not change:lithium, calcium

Other metals

More than oneoxidation number

Roman numerals to specify charge:iron(II), iron(III),tin(II), tin(IV)

BinaryTwo elements

Ternary More than two elements

Binary Molecular Compounds

non metal + stem of second non metal

ending ide

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Formula-to-Name Acids

Acids are molecular compounds that often behave like they are made of ions.

All names have acid at end. Binary Acids = Hydro- prefix + stem of

the name of the nonmetal + -ic suffix. Oxyacids:

If polyatomic ion ends in –ate = Name of polyatomic ion with –ic suffix.

If polyatomic ion ends in –ite = Name of polyatomic ion with –ous suffix.

Hydrates Ionic compounds that crystallize with

water occluded in their crystal structure.

NaCO3 ·10H2O

BaCl2 · 2H2O

Co(NO3) 2 · 6H20