Final Review

Measurement • Accuracy• Precision• What are the rules for

reading instruments in the lab?

• How do you decide the best instrument to use in the lab?

Significant Figures

• What are the rules?

• 0.5260

• 5.02

• 5020

• 0.00502

• 500.

Significant Figures

• What are the rules for addition and subtraction?

• 5.20 + 6.2 = 5.21 – 5.234 =

• What are the rules for multiplication and division?

• 5.02 x 5.203 = 5.54 x 5.4/5 =

Chemical and Physical Change

• How do we know something is a chemical change?

• What are some chemical changes?

• How do we know something is a physical change?

• What are some physical changes?

Chemical and Physical Properties

• What is a chemical property? Physical property?– Melting point - length– Corrosive - toxicity– Solubility - mass– Density - Flammability– Boiling point - combustibility

Atomic Structure

• What is an isotope?• How many protons,

neutrons, and electrons?Br

80 35

Carbon- 12Carbon- 12

S3216

Atomic Structure

Element Atomic Mass

Protons Neutrons Electrons

Sodium -24 11 11

Oxygen-18 18 10 10

Calcium-41 41 20 18

Electron Configuration

Electron Configuration

• What is the electron configurations for:– Sodium– Fluorine– Phosphorus– Calcium– Iron– Bromine

What are the shorthand configurations?

Ionization energy, electronegativity

Electron affinity INCREASE

Atomic size increases, shielding constant

Ionic size increases

Periodic Trends

• Which atom is larger and has the greater electronegativity?– Sodium or chlorine– Magnesium or barium– Oxygen or lithium

• Which ion is smaller? – Calcium or barium– Magnesium or silicon– Chlorine or silicon

Compounds

• Identify each of the following as ionic or covalent. Write the name of each compound.– NaBr F3H9

– P3N7 Mg3P2

– O4Br6 NaCl

– Ca3N2 SrI2

– B2I8 BaBr2

Two Types of Compounds

Smallest piece

Melting Point

State

Types of elements

Formula Unit Molecule

Metal and Nonmetal

Nonmetals

solidSolid, liquid or gas

High >300ºC Low <300ºC

Ionic Molecular

Naming Compounds

• Identify each of the following as ionic or covalent. Write the name of each compound.– NaBr F3H9

– P3N7 Mg3P2

– O4Br6 NaCl

– Ca3N2 SrI2

– B2I8 BaBr2

Write the formulas for these• Lithium sulfide

• tin (II) oxide

• tin (IV) oxide

• Magnesium fluoride

• Copper (II) sulfate

• Iron (III) phosphide

• gallium nitrate

• Iron (III) sulfide

Polar-Covalent bonds

Nonpolar-Covalent bonds

Covalent BondsCovalent Bonds

Electrons are unequally shared Electronegativity difference between .3 and 1.7

Electrons are equally shared Electronegativity difference of 0 to 0.3

PolarityPolarity A molecule, such as HF, that has a A molecule, such as HF, that has a

center of positive charge and a center center of positive charge and a center of negative charge is said to be polar, of negative charge is said to be polar, or to have a dipole moment.or to have a dipole moment.

+

FH

Polar/Non-Polar

• O2

• CH3Cl

• HCl

• CCl4• N2

• NO2

Single Replacement Reactions

Br2 (l) + NaI (aq)

Ca (s) + HBr (aq)

Cu(NO3)2 (aq) + Au (s)

Fe (s) + H2SO4 (aq)

Double Replacement

1. NaCl (aq) + AgNO3 (aq)

2. SrBr2 (aq) + AgNO3 (aq)

3. Li2SO4 (aq) + Pb(NO3)2 (aq)

4. K2CO3 (aq) + Pb(NO3)2 (aq)

Calculating Formula MassCalculate the formula mass of magnesium Calculate the formula mass of magnesium carbonate, MgCOcarbonate, MgCO33..

24.31 g + 12.01 g + 3(16.00 g) 24.31 g + 12.01 g + 3(16.00 g) ==

84.32 g84.32 g

Calculations with Moles:How many grams of lithium are in 3.50 moles of lithium?

3.50 mol Li= g Li

1 mol Li

6.94 g Li24.29

Calculations with Moles:Converting grams to moles

How many moles of lithium are in 18.2 grams of lithium?

18.2 g Li= mol Li

6.94 g Li

1 mol Li2.62

Calculations with Moles:Using Avogadro’s Number

How many atoms of lithium are in 3.50 moles of lithium?

3.50 mol Li = atoms Li

1 mol Li

6.022 x 1023 atoms Li 2.11 x 1024

Calculations with Moles:How many atoms of lithium are in 18.2 g of lithium?

18.2 g Li

= atoms Li

1 mol Li 6.022 x 1023 atoms Li

1.58 x 1024

6.94 g Li 1 mol Li

(18.2)(6.022 x 1023)/6.94

Periodic Table

MolesA

MolesB

Massg B

Periodic Table

Balanced Equation

Massg A

•Decide where to start based on the units you are given

•and stop based on what unit you are asked for

For example...• If 10.1 g of Fe are added to a solution of

Copper (II) Sulfate, how much solid copper would form?

• Fe + CuSO4 Fe2(SO4)3 + Cu

• 2Fe + 3CuSO4 Fe2(SO4)3 + 3Cu 10.1 g Fe

55.85 g Fe1 mol Fe

2 mol Fe3 mol Cu

1 mol Cu63.55 g Cu

= 17.3 g Cu

Calculations involving Specific Heat

cp = ___q__ m x T

q = cp x m x T

cp = Specific Heat

q = Heat lost or gained

T = Temperature change

OR

Gas Laws

1 A gas mixture containing O2, N2, and CO2 has a pressure of 250 mm Hg. If the pressure of O2, is 50 mm Hg and the pressure of N2 is 175 mm Hg, find the pressure of CO2.

2 Five liters of air at –50 C is warmed to 100 C. What is the new volume if the pressure remains constant?

3 How many moles of gas are present if the volume is 2.5 L, pressure is 0.95 atm, and temperature is 25 C?

Gas Laws

• How many moles of air are there in a 2.0 L bottle at 19ºC and 747 mm Hg?

• What is the pressure exerted by 1.8 g of H2 gas exert in a 4.3 L balloon at 27ºC?

Molarity

• What is molarity?• What is the molarity of a solution prepared by

dissolving 16.0 g of BaCl2 in enough water to give 450 ml of solution?

• What is the molarity of the solution produced when 145 g of sodium chloride is dissolved in sufficient water to prepare 2.75 L of solution?

• How many grams of potassium chloride are needed to prepare 0.7500 L of a 1.50 M solution of potassium chloride?

Titration Practice1. If it takes 250 mL of 0.5 M LiOH to neutralize 50 mL

of an HNO3 solution, what is the concentration of the HNO3?

2. If it takes 100 mL of 1.0 M HCl to neutralize 250 mL of Ca(OH)2 solution, what is the concentration of the Ca(OH)2 solution?

3. If it takes 50 mL of 0.5 M KOH solution to completely neutralize 125 mL of sulfuric acid solution (H2SO4), what is the concentration of the H2SO4 solution?

Rate of Reaction

• What are the factors that increase the rate of reaction?

Table – VSEPR Structures