Exam 1

Made up of atoms
Matter

columns 1A – 2A (2 groups)

columns 3A – 8A

Very predicable behavior

Main groups

3B – 2B (8 groups, 10 columns)

Variable chemical properties

Transition Metals
14 groups between 3B and 4B
Inner Transition Metals

Left side of the zigzag line in the periodic table (except for hydrogen)

Hard, solide, malleable(except Hg, which is liquid)

Conducts electricity, not brittle

 

Metals

Right side of the zigzag line in the periodic table

Gases

Not malleable or brittle

Insulators of electricity

Nonmetals

Tend to lie along the zigzag line in the periodic table

Properties of metals and nonmetals

Metalloids
React with water to produce acids (-1 anions)
Halogens

column 1A

Form an alkali solution when combined with water (+1 cations when in water)

alkali metals

column 2A

+2 cations with water

Most insoluable in water

alkaline earth metals
Chemically inert
Nobel gases

Independent of sample size

Temperature

Melting Point

Density

Intensive properties

Dependent on sample size

Length

Volume

Extensive properties

Amount of matter in an object

All matter has this

Mass
Describes anything with a physical presence – anything you can touch, taste, or smell
Matter

Measures the force with which gravity pulls on an object

 

Weight

How close to the true value a given measurement is

Single measurement: percent error

Series of measurements: average

 

Accuracy

How well a number of independent measurements agree with each other.

Characterized by the standard deviation.

Precision

the number of meaningful digits in a measured or calculated quantity. They come from uncertainty in any measurement

Generally the last digit in a reported measurement is uncertain

Exact numbers and relationships (7 days in a week, 30 students in a class) effectively have an infinite number of this

Significant figures

 

Mass is neither created nor destroyed in chemical reactions

Atoms do nto mutate in reactions

Law of Conservation of Mass

Differenct samples of a pure chemical substance always contain the same proportion of elements by mass

A pure substane will always have the same type and mass of atoms

Law of Definite Proportions
Elements are made up of tiny particles
Atoms

Matter is made up of atoms, atoms combine in whole numbers, in reactions, atoms rearrange

Each element is characterized by the mass of its atoms. Atoms of the same element have the same mass, but atoms of different elements have different masses

Chemical combination of elements to make different substances occurs when atoms join together in small whole-number ratios

Chemical reactions only rearrange the way that atoms are combined, the atoms themselves don’t change

Dalton’s Atomic Theory and the Law of Multiple Proportions
Elements can combine in different ways to form different substances, whose mass rations are small whole-number multiples of each other.
Law of Multiple Proportions
J.J. Thomson proposed that cathode rays must consist of tiny negatively charged particles called
Electrons

Rutherford bombarded gold foil with alpha particles.  Although most of the alpha particles passed through the foil undeflected, approximately 1 in every 20,000 particles were deflected.  A fraction of those particles were deflectedc back at an extreme angle.

He proposed that the atom must consist mainly of empty space with the mass concentrated in a tiny central core.

His experiment showed that the mass of the atom is found in the

Atomic Nucleus
Alpha rays are scattered only when they hit nucleus. The nucleus must be very small relative to the atom volume
Interpretation of Rutherford’s Results

The mass of an atom is in the nucleus

The proton and neutrons have equal mass

The electron is negative

The proton is positive

Structure of Atoms
Number of protons in an atom’s nucleus.  Equivalent to the number of electrons around the atom’s nucleus.
Atomic Number
The sum of the number of protons and the number of neutrons in an atom’s nucleus.
Mass Number
Atoms with identical atomic numbers but different mass numbers
Isotope
The weighted average of the isotopic masses of the element’s naturally occurring isotopes
Atomic Mass
Matter consists of ____, elements or compound
Pure substances
Mixtures are
hetero or homogeneous
Contain atoms connected by covalent bonds (collection of like molecules is a pure molecular compound)
Molecules
Results when two atoms share several (usually two) electrons.; Typically a nonmetal bonded to a nonmetal.
Covalent Bond
A transfer of one or more electrons from one atom to another.; An electrostatic attraction between charged particles.; Typically a metal bonded to a nonmetal.
Ionic Bond

A class of compounds

Positive and negative atoms associate to form a neutral salt

Ionic compounds
A charged particle
Ion
A positively charged particle.; Metals tend to form these
Cation
A negatively charged particle.; Nonmetals tend to form these
Anion
____ are not individual molecules, rather a neutral aggregate of positive and negative ions
Salts

Form when metals give up electrons to nonmetals

The metal cation is positive and the nonmetal anion is negative

Binary salts

Class of compounds

____ release protons (H+) and ____ release hydroxide (OH-)

Acids and bases

Compounds that are easiest to name

Identify the metal cation and its charge for the main group

1A to 3A the cation charge is the group number

Binary ionic compounds

Identify the nonmetal anion

The charge for atoms from 5A to 7A is group number -8

Naming Ionic Compounds
The name must indicate the charge since they vary for most for
transition metals
Take the name of the element
cations

Take the root of the nonmetal name and ide

The salt is the cation name plus the anion name

anions

Fro molecular compounds, the number of each atom type must be given

Use prefixes mono, di, tri, tetra, penta, hexa, hepta, etc.

Naming binary molecular, covalent compounds

The first element listed is more cation like and takes the name of the element

The second element listed is more anion like and takes the name of the element with an ide modification to the ending

Naming binary molecular, covalent compounds

Named after the anion

ite to ous

ate to ic

Complex acids

When hydrogen is listed first

Neutral

The correct number of hydrogens (+) have to be added to make it neutral

Acid
A balanced chemical equation show that the _____ is adhered to
law of conservation of mass
Sum of atomic masses of all atoms in a molecule
Molecular/Formula Mass
Sum of atomic masses of all atoms in a formula unit of any compound, molecular or ionic
Formula/Molecular Mass
One mole of any substance contains 6.022 * 10^23 formula units
Avogadro’s Number
One mole of any substance is equivalent to its
Molecular/Formula Mass
The relative proportions in which elements form compounds or in which substances react
Stoichiometry
The amount actually formed in a reaction
Actual Yield
The amount predicted by calculations
Theorectical Yield
(actual yield)/(theorectical yield) * 100
Percent Yield
The reactant that is present in limiting amount.  The extent to which a chemical reaction takes place depends on this
Limiting Reactant
Any of the other reactants still present after determination of the limiting reactant
Excess Reactant

The number of moles of a substance dissolved in each liter of solution. 

(moles of solute)/(liters of solution)

Molarity
A homogenous (well-mixed) mixture
Solution
The dissolved substance in a solution
Solute
The major component in a solution
Solvent

Concentrated solution + solvent = _____

MiVi = MfVf

dilute solution
A procedure for determing the concentration of a solution by allowing a carefully measured volume to react with a solution of another substance (the standard solution) whose concentration is known
Titration

Expressed by identifying the elements present and giving the mass percent of each

(mass atom X)/(formula mass)*100

Percent Composition
It tells only the rations of the atoms in a compound
Empirical Formula
It tells the actual numbers of atoms in a compound.  It can be either the empirical formula or a multiple of it.
Molecular Formula
Sulfide
S-2
Sulfite
SO3^-2
Sulfate
SO4^-2
Nitride
N^-3
Nitrite
NO2^-1
Nitrate
NO3^-1
Phosphide
P^-3
Phosphite
PO3^-3
Phosphate
PO4^-3
Carbide
C^-4
Carbonate
CO3^-2
Chloride
Cl^-1
Hypochlorite
ClO^-1
Chlorite
ClO2^-1
Chlorate
ClO3^-1
Perchlorate
ClO4^-1
Bromide
Br^-1
Hypobromite
BrO^-1
Bromite
BrO2^-1
Bromate
BrO3^-1
Perbromate
BrO4^-1
Iodide
I^-1
Hypoiodite
IO^-1
Iodite
IO2^-1
Iodate
IO3^-1
Periodate
IO4^-1
Hydroxide
OH^-1
Cyanide
CN^-1
Cyanate
CNO^-1
Hydrogen phosphate
HPO4^-2
Hydrogen sulfate
HSO4^-1
Bicarbonate
HCO3^-1
Ammonium
NH4^+1