Bellwork
Monday, 10/29
To the right is
a label from a
popular food
item. Name
five elements
that are
found on this
food label.
I have the test graded I will show you the grades once the we finish
Test scores:
Lab Test WS 1st Period
CHEMISTY I
CHAPTER 6
Molecule- the smallest electrically
neutral unit of a substance that still
has the properties of that substance
-made up of two or more atoms that
act as a unit Ex.
H
2O
CH
4
O
2CO
2
Molecular
compound-
-usually composed
of molecules
-Have
low melting
& boiling points
-Are usually made
up of two or more
NONMETALS
Sugar, a compound made of carbon, hydrogen and oxygen, melts easily in a hot pan.
(AKA: Covalent)
Which of the following are molecular compounds? H2SO4 Pb(NO3)2
Which of the following is molecular
and which is ionic?
•NaCl
•H
2O
•CaCO
3•CO
•Al
2Cl
3•CF
4•O
3Hint: If it is not
triatomic
molecule- contain
three atoms of
the same element
Molecular Compounds and Acids
Binary Molecular Compounds
When naming binary molecular compounds,
prefixes are used to tell how many of each atom is in the formula.
CO2 carbon dioxide
The prefix mono- is never used with the first element. The prefix list in on page 159.
1- 6-2- 7-3- 8-4- 9-5- 10-mono tri tetra nona octa hepta penta hexa deca di
What prefixes would you use to describe a compound with four carbons and 10
Example:
phosphorous tribromide
ICl3
P2O5
SF6
tetraarsenic hexoxide
PBr3
iodine trichloride
diphosphorous pentoxide
Sulfur hexafluoride
Acids and Bases
You need to know the names and
formulas of these most common acids:
HCl
H2SO4
HNO3
HC2H3O2
H3PO4
hydrochloric acid sulfuric acid
nitric acid acetic acid
Ions-
atoms or groups of atoms
that have a positive or negative
Let’s Practice!
Sodium loses an electron Na __________
Magnesium loses two electrons Mg __________
Chlorine gains one electron Cl __________
Phosphorus gains three electrons P __________
Na2+
Mg2+
Cl
-P3+
Atom “X” loses one
electron. What is its new charge?
Cation-
-positively charged ion -electrons were lost
-metals tend to form cations
-name of monatomic cation is the same as the element
We are positive about
Examples:
Na Na+ + e
-Ca -Ca2+ + 2e
-Anion
-
negatively charged ion -electrons were gained-nonmetals tend to form anions
-name of monatomic anion ends in –ide
Cl + e- Cl -O + 2e- O 2-N + 3e- N
3-Examples:
We feel negatively about ants!
Classify the following as cations or anions. H+ ___________
K+ ___________
F- ____________
C+4 ___________
Bellwork, Tuesday
How many protons, neutrons and electrons are in this atom?
Based on what you know about the charge of a proton and an electron, what is the overall charge of
this atom? What element is this atom?
Red =protons
Ionic
compound--composed of cations and anions
-usually metal & nonmetal -electrically neutral
-mostly solids at room temperature
-high melting points
-the more positive element always comes first
Monatomic Ions
The charge of a monatomic ion can often be determined by the element’s position on the periodic table:
Group 1A: 1+ Ex. Na+
Group 2A: 2+ Ex. Ca2+ Group 3A: 3+ Ex. Al3+ Group 5A: 3- Ex. N
3-Group 6A: 2- Ex. O
2-Group 7A: 1- Ex. F
Alkali metals have a charge of +1
Alkaline Earth metals have a charge of +2
The boron family has a charge of +3
The carbon family has a charge of + or -4
The nitrogen family has a charge of -3
The oxygen family has a charge of -2
The halogens have a charge of -1
The noble gasses have no charge and are inert
Transition
Elements in Group 0 (8) do not form
ions. Elements in Group 4 rarely form ions. They tend to react by sharing
electrons (forming covalent
compounds) instead of transferring electrons.
Group 8 Electron configuration = s2p6
What causes the charges for each group on the periodic table?
The charges indicate how many electrons an atom will gain or lose.
Octet Rule and Stabi
lity
The goal of an atom is to become stable. An atom will gain, lose, or share electrons in order for that stability to be attained.
Stability is determined by the octet rule:
• Ex: Potassium (and all of group 1) has 1 valence electron, so it will lose 1 electron making its charge +1.
Remember that electrons are
Examples: O P F Na Mg Al
Sr 2+
Transition Metal ions (See Table 6-3 pg 144):
Most transition metals form more than one ion. They are stable losing
varying numbers of electrons. The
Exceptions:
What is the formula for the
following transition metals as ions?
Copper (I)
Iron (III)
Lead (II)
The mercury(I) ion is unique. It only exists in pairs of mercury(I) ions (like Siamese twins). Its
Quick Check Quiz: Have you been studying your ions?
sodium _______ chromous ________
selenide _______ tin(IV) ________
Na
+Cr
2+Se
Rubidium loses one electron _____
Silver loses one electron _____
Arsenic gains three electrons _____
Sulfur gains two electrons _____
Lithium loses one electron _____
Tuesday Bellwork
Wednesday Bellwork
Name the following compounds or
write the formulas, as appropriate.
CCl
4Thursday Bellwork
Practice your ions! Write the symbol and charge for the following ions.
Nitride
Oxide
Magnesium ion
Rubidium ion
Friday Bellwork
Match the following ions with their names. ___NO3- A. nitride
___CN- B. silver ion
___Ag+ C. cyanide
___NH4+ D. ammonium
___N3- E. chloride
Polyatomic Ions
(Table 6-4, pg 147):
-tightly bound groups of atoms that behave as a unit and carry a
charge
The only positively charged
polyatomic ion that we need to
Ions that end in –ite or –ate contain
oxygen. In a series such as sulfate and sulfite, the –ite ending has one less
oxygen than the –ate ending.
Sulfite SO3
2-SO32- sulfite
SO42- sulfate
NO2- nitrite
Binary compounds- 2 elements Binary ionic compounds-
1 metal + 1 nonmetal
Examples:
NaCl
NaF
CaCl2
metal nonmetal
When naming ionic compounds,
simply name the ions as they appear in the formula.
When naming ionic compounds
Example:
AlCl3 KBr FeCl2 FeCl3
aluminum chloride potassium bromide iron(II) chloride
When writing the formula for an
ionic compound, the charges of the ions must cancel out to give the
Example:
sodium chloride
Na
+Cl
-1 1
magnesium iodide
Mg2+ I
-1 2
magnesium nitride
Mg 2+ N
3-2 3
strontium selenide
Sr2+ Se
2-2 2
rubidium iodide
aluminum oxide
Rb+ I
-RbI
Al3+
O
When writing formulas containing
polyatomic ions, use parentheses around multiple polyatomic ions.
ammonium carbonate
NH4+ CO 3
2-2 1
strontium hydroxide
Sr2+ OH
-1 2
calcium nitrate
Ca2+ NO 3
-1 2
aluminum phosphate
Al3+ PO
4
3-3 3
Monday Bellwork
Practice this ion quiz:
NO3- _______________________
Mercury (II) _______________________
Ag+ _______________________
CN- _______________________
Potassium _______________________ Bromide _______________________
When naming ionic compounds
containing a transition metal, don’t forget to include the Roman
numeral for the charge.
Ex. FeCl2
iron(II) chloride FeCl3
Distinguish Between the
two types of compounds!
Molecular
Ionic
•Two or more nonmetals
•Low melting point •Low boiling point •Example CO2
•Metal and nonmetals
•High melting point •High boiling point
•Solid at room temperature •Electrically neutral
Which of the following is molecular and which is ionic?
NaBr
CO2
O3
NO
KCl
AlBr3
Chemical formula- shows the number and kinds of atoms in the smallest
representative unit of the substance.
Molecular formula- chemical formula
written for a molecule
Ex. CO
2O
2or H
2O
2Formula unit- chemical formula
written for an ionic compound.
Tuesday Bellwork
Name the following compounds.
NaBr _____________________________
Al(OH)3 ___________________________
NH4F _____________________________
Li2SO3 ____________________________
CaBr2 ____________________________
KMnO4 ___________________________
Fe(NO3)2__________________________
Law of Definite Proportions-
In all samples of any chemical compound, the elements are always combined in the same proportion by mass.
Law of Multiple Proportions- Whenever two elements form more than one
compound, the different masses of one element that combine with the same
Wednesday Bellwork
Using the food label shown, write two
Thursday Bellwork
Write the formulas for these compounds.
Potassium chlorite
Calcium hydrogen carbonate
Dichlorine heptoxide
Trisilicon tetranitride
Sodium dihydrogen phosphate
Friday Bellwork