Chem 101 Review

Fall 2012

Elements, Atoms, Ions What should you know?

Elements

in nature

symbols

Constant composition

chemical formula

Dalton’s atomic theory

Atomic structure

what makes up the atom

ions

isotopes

Periodic table

Elements, Atoms, Ions What should you know?

Elements

in nature

symbols

Constant composition

chemical formula

Dalton’s atomic theory

Atomic structure

what makes up the atom

ions

isotopes

Periodic table

Oxygen O (O2)

Silicon Si

Aluminum Al

Iron Fe

Calcium Ca

Carbon C

Hydrogen H (H2)

Elements, Atoms, Ions What should you know?

Elements

in nature

symbols

Constant composition

chemical formula

Dalton’s atomic theory

Atomic structure

what makes up the atom

ions

isotopes

Periodic table

A compound always has the

same composition

Represented by a formula that

gives the relative number of

atoms in the compound

Carbon dioxide CO2

Elements, Atoms, Ions What should you know?

Elements

in nature

symbols

Constant composition

chemical formula

Dalton’s atomic theory

Atomic structure

what makes up the atom

ions

isotopes

Periodic table

• All elements are

composed of atoms.

• All atoms in an element

are identical,

• Atoms of different

elements are different.

• Atoms combine to form

chemical compounds.

• Atoms are not created or

destroyed in chemical

reactions.

Elements, Atoms, Ions What should you know?

Elements

in nature

symbols

Constant composition

chemical formula

Dalton’s atomic theory

Atomic structure

what makes up the atom

ions

isotopes

Periodic table

Elements, Atoms, Ions What should you know?

Elements

in nature

symbols

Constant composition

chemical formula

Dalton’s atomic theory

Atomic structure

what makes up the atom

ions

isotopes

Periodic table

• Positive and negative

ions combine to form

ionic compounds.

• The net charge for the

compound is 0.

• Al3+ + N3- → AlN

Elements, Atoms, Ions What should you know?

Elements

in nature

symbols

Constant composition

chemical formula

Dalton’s atomic theory

Atomic structure

what makes up the atom

ions

isotopes

Periodic table

• Atoms of an element with

different numbers of neutrons

are called isotopes.

Elements, Atoms, Ions What should you know?

Elements

in nature

symbols

Constant composition

chemical formula

Dalton’s atomic theory

Atomic structure

what makes up the atom

ions

isotopes

Periodic table

Periodic table What should you know?

Elements Whats in the box? symbol and name atomic number (#p = #e) atomic mass (#p = #n) metals and nonmetals group, column, family principal energy level relative atomic size relative ionization energy relative reactivity relative electronegativity

Ions charge on common ions

11

Na

23

22 Na

23

Na

11

22 Na vs 11

Periodic table What should you know?

Elements

symbol and name

atomic number (#p=#e)

atomic mass (#p = #n)

metals and nonmetals

group, column, family

principal energy level

relative atomic size

relative ionization energy

relative reactivity

relative electronegativity

Ions

charge on common ions

Periodic table What should you know?

Elements

Sodium What is the number and name of group?

Na

What is the principal energy level?

What charge is on a sodium ion?

Which is larger, a sodium atom or ion?

Which is larger, a sodium atom or a chlorine atom?

Which is larger, a sodium atom or a potassium atom?

Which is more reactive, sodium or potassium?

Which has greater electronegativity, sodium or fluorine?

Periodic table What should you know?

Ions

What is the charge on ions formed from the group 2 alkaline

earth metals?

What is the charge on ions formed from the group 7 halogens?

What is the charge on ions formed from group 6?

Since compounds must have a neutral charge, what would be

the formula for a compound formed when calcium and chlorine

react?

Write an equation for the reaction of calcium and chlorine?

Nomenclature

Nomenclature Flowchart Ionic compounds (metal and nonmetal) Q Name CaBr2

Q Name Fe2S3 Q Name MgCO3

Covalent compounds (nonmetals) Q Name SO2 Q Name N2O4

Acids Table 5.5 and 5.6 Q Name HCl(aq) Q Name H2SO4(aq)

Polyatomic ions Q Name PO4

3- Q Hydroxide ion

Single-Charge Multiple-Charge Metal Metal

Name the metal

Indicate metal charge by (Roman #) or Latin

name (-ous or –ic)

+ 1 nonmetal

+ 2 nonmetals

Name the polyatomic ion Nonmetal name

with –ide ending

*Metal + Nonmetal

Chemical Formula

2 Nonmetals

1) Use Greek prefixes to indicate subscripts

2) second element –ide ending

H + Nonmetal(s)

Name as acids

* Treat NH4+

as a metal when

naming compounds

What should you know?

Chemical Bonding What should you know?

Filled shells are chemically

stable

Octet rule

How atoms bond

Electron dot formulas

Lewis structures

Not all e- participate in chem bonding

Inner shells: core electrons

Valence shell: outermost shell

chem reactions and bonding

Can be found whenever a noble gas

element is reached on the periodic

table

Atoms form ions that have the same

number of valence electrons as the

outermost shell of noble gas element

Chemical Bonding What should you know?

Filled shells are chemically

stable

Octet rule

How atoms bond

Electron dot formulas

Lewis structures

Hydrogen and helium have shells

filled with 2e-

The first few periods of the tables

have a maximum of 8 e- in the

valence shell

Groups I and II lose e- and become

cations

Groups VI and VII gain e- to become

anions

Chemical Bonding What should you know?

Filled shells are chemically

stable

Octet rule

How atoms bond

Electron dot formulas

Lewis structures

Each atom acquires 8e- in their outer

shell

Transfer e-: ionic bond

Example: potassium bromide KBr

Potassium (metal) gives up 1e- K1+

Bromine (nonmetal) takes 1 e- Br1-

Share e-: covalent bond

Example: Hydrogen chloride HCl

hydrogen has 1valence e-

chlorine has 7 valence e-

Hydrogen shares 1e- with chlorine

Chlorine shares 1 e- with hydrogen

Chemical Bonding What should you know?

Filled shells are chemically

stable

Octet rule

How atoms bond

Electron dot formulas

Lewis structures

Number of dots represent number of

valence electrons

Hydrogen chloride

H Cl

e- have: 1 7

e- want 2 8

10e- minus 8e- = 2e-

2e-/2e- = 1 shared bond

Chemical Quantities What should you know?

Balanced equation

Mole concept

Percent composition

Empirical formula

Molecular formula

Relative # of molecules of

reactants and products

C(s) + O2(g) → CO2(g)

Chemical Quantities What should you know?

Balanced equation

Mole concept

Percent composition

Empirical formula

Molecular formula

Mass of 1.00 mole element is

equal to the atomic mass in

grams

1.00 mole = 6.02 x 1023 units

Avogadro’s number

1.00 moles of carbon atoms

weighs 12.0 grams and has

6.02 x 1023 atoms of C

Equalities for carbon

Chemical Quantities What should you know?

Balanced equation

Mole concept

Percent composition

Empirical formula

Molecular formula

Q How many moles are in 6.02

grams of carbon?

Q How many atoms are in 2.00

moles of carbon?

Q How many grams are in 2.00

moles of carbon?

Chemical Quantities What should you know?

Balanced equation

Mole concept

Percent composition

Empirical formula

Molecular formula

Percent by mass of each

element in a compound

Percent = part in grams x 100%

whole

What is the percent of C in CO2?

1C = 12.0 g = 12.0 g

2O = 16.0 x 2 = 32.0 g

44.0 g

12.0 g/ 44.0 g x 100% = 27.3%

Chemical Quantities What should you know?

Balanced equation

Mole concept

Percent composition

Empirical formula

Molecular formula

Empirical formula is the

simplest whole number ratio of

the atoms in a molecule

Molecular formula is a multiple

of the empirical formula and

along with the structure of the

molecule, identifies the

molecule.

Chemical Equations What should you know?

Balance an equation

Diatomic molecules

Correct formulas

Same # of each type of atom on both

sides of the equation

Whole # coefficients

Start with the most complex formula

first

Keep polyatomic ions together

Q __K(s) + __H2O(l) →__H2(g) + __KOH(aq)

Chemical Equations What should you know?

Balance an equation

Diatomic molecules

Occur naturally

H2

O2

N2

?

Cl2

Br2

I2

Q Which gas is missing ?

Reactions What should you know?

Signs of a reaction

Forces that drive a reaction

Aqueous solutions

Equations

Molecular

Complete Ionic

Net ionic

Solubility tables

Classify reactions

Activity series

• Gas

• Precipitate

• Perm. color change

Q What is a 4th sign that

a reaction is taking

place?

Reactions What should you know?

Signs of a reaction

Forces that drive a reaction

Aqueous solutions

Equations

Molecular

Complete Ionic

Net ionic

Solubility tables

Classify reactions

Activity series

• Gas

• Precipitate

• Perm. color change

• Heat or light given off

Reactions What should you know?

Signs of a reaction

Forces that drive a reaction

Aqueous solutions

Equations

Molecular

Complete Ionic

Net ionic

Solubility tables

Classify reactions

Activity series

• Solid forms

• Water forms

• Gas forms

• Transfer electrons

Reactions What should you know?

Signs of a reaction

Forces that drive a reaction

Aqueous solutions

Equations

Molecular

Complete Ionic

Net ionic

Solubility tables

Classify reactions

Activity series

• When ionic compounds

dissolve in water, the

cations and anions

separate from each other

• Ions are free to move

• Dissociation

K2SO4(aq) → 2K+(aq) + SO4

2-(aq)

Website example

Reactions What should you know?

Signs of a reaction

Forces that drive a reaction

Aqueous solutions

Equations

Molecular

Complete Ionic

Net ionic

Solubility tables

Classify reactions

Activity series

Q NaNo3 soluble or insoluble

Q Mg(OH)2 soluble or insoluble

Reactions What should you know?

Signs of a reaction

Forces that drive a reaction

Aqueous solutions

Equations

Molecular

Complete Ionic

Net ionic

Solubility tables

Classify reactions

Activity series

Chemical reactions can be divided

into five categories:

Combination or Synthesis

Decomposition

Single-Replacement

Double-Replacement

Neutralization

Reactions

Q: Match each reaction with its type

A) BaCl2(aq) + K2CrO4(aq) → BaCrO4(s) + 2 KCl(aq)

B) H2SO4(aq) + 2 KOH(aq) → K2SO4(aq) + 2 H2O(l)

C) Fe(s) + CuSO4(aq) → FeSO4(aq) + Cu(s)

D) CaCO3(s) → CaO(s) + CO2(g)

E) 4 Fe(s) + 3 O2(g) → 2 Fe2O3(s)

Combination or Synthesis

Decomposition

Single-Replacement

Double-Replacement

Neutralization

Stoichiometry What should you know?

Balanced Equation

Interpret #moles of reactants

and products

Calculate the mass of

reactants and products

Limiting Reactants

Which reactant limits how

much product is formed

Which reactant is in excess

Percent Yield

• Stoichiometry refers to the

quantitative relationship

between reactants and

products in a chemical

reaction.

Stoichiometry What should you know?

Balanced Equation

Interpret #moles of reactants

and products

Calculate the mass of

reactants and products

Limiting Reactants

Which reactant limits how

much product is formed

Which reactant is in excess

Percent Yield

Q. How many moles of oxygen

gas react with 2.25 moles of

magnesium to make

magnesium oxide?

2 Mg(s) + O2(g) → 2 MgO(s)

Stoichiometry What should you know?

Balanced Equation

Interpret #moles of reactants

and products

Calculate the mass of

reactants and products

Limiting Reactants

Which reactant limits how

much product is formed

Which reactant is in excess

Percent Yield

Q. How many moles of oxygen

gas react with 2.25 moles of

magnesium to make

magnesium oxide?

2 Mg(s) + O2(g) → 2 MgO(s)

Q. How many grams of MgO are

formed?

Hint: find the molar mass of MgO

Mg = 24.3 g/mole

O = 16.0 g/mole

MgO =

Stoichiometry What should you know?

Balanced Equation

Interpret #moles of reactants

and products

Calculate the mass of

reactants and products

Limiting Reactants

Which reactant limits how

much product is formed

Which reactant is in excess

Percent Yield = actual yield (g) x 100%

theoretical yield (g)

Q. How many moles of oxygen

gas react with 2.25 moles of

magnesium to make

magnesium oxide?

2 Mg(s) + O2(g) → 2 MgO(s)

Q. How many grams of MgO are

formed? 90.7g

Q. If only 45.4g of MgO form,

what is the percent yield?

Stoichiometry What should you know?

Balanced Equation

Interpret #moles of reactants

and products

Calculate the mass of

reactants and products

Limiting Reactants

Which reactant limits how

much product is formed

Which reactant is in excess

Percent Yield

If 2 moles of H2 and 2 moles of O2

react, how many moles of

water are formed?

2H2 + O2 → 2H2O

Q. Which is the limiting reactant?

H2 or O2

Properties of Gases What should you know?

• What causes gas pressure

• What is absolute 0

• What is vapor pressure

• How does volume affect pressure

• How does temperature affect pressure

• How do the number of molecules affect

pressure

Chapter 4: Periodic table What should you know?