Chapter 3: Molecules, Compounds, and Chemical Equations
HCO3(-)
Hydrogen Carbonate (bicarbonate)
HSO3 (-)
Hydrogen Sulfate (or bisulfate)
OH(-)
Hydroxide
ClO (-)
Hypochlorite
Iodine
I-
Which of the following is an ionic compound? A. LiCl B. NO2 C. PCl3 D. CF4 E. SeBr2
A
SO3 (-)
Sulfite
Formula mass
Sum of atomic masses o reach element in chemical formula
Molecular
The actual number and types of atoms in a molecule
Anions
Non-metals or polyatomic ions
Cl(O1-)
(Hypo)chlor(ite)
Cl(O4-)
(Per)chlor(ate)
Polyatomic
(many atoms) P4, S8, Se8
Diatomic
(to atoms) N2, O2, F2, Cl2, Br2, I2, H2 (Start at 7 make a 7)
How to name a formula that starts with hydrogen?
1. Add hydro in front the base name of nonmetal 2. Add -ic to -ate; add -ite to -ous (no -hydro if -ite) 3. Add "acid" at the end of the name
Writing Formulas
1. Write symbols and ion charges (periodic table) 2. Charge becomes subscript for the other ion. 3. Reduce subscripts to smallest whole number ratios 4. Check charge neutrality
Molecules
2 or more atoms tightly bonded together When more than one type of atom combines to form a molecule in fixed definite proportions Molecule has different properties than individual elements many elements are found in molecular form
Molecular models
3D representations Ball and stick (modeling kit) Space filling (shows how much space electrons take up)
C2H3O2 (-)
Acetate
NH4 (+)
Ammonium
Covalent
Atoms share electrons and between non-metals
Ionic
Atoms transfer electrons between nonmetals and metal, oppositely charged ions (cation and anions)
Which of the following is an ionic compound? A. SCl2 B. Mg3(PO4)2 C. Cl2O D. CH2O E. PF5
B
Molecular compound is what type of bond?
Covalent
Bromine
Br-
Which of the following contains BOTH ionic and covalent bonds? A. CaI2 B. COS C. CaSO4 D. SF6 E. None of these contain both
C. Calcium is a metal SO4 is a covalent bond
Transition Metals
Can have different charges Use parentheses and numeral to indicate change Ex: CrBr3 Chromium (111) Bromide
CO3(2-)
Carbonate
Cl(O3-)
Chlor(ate)
Cl(O2-)
Chlor(ite)
ClO3 (-)
Chlorate
ClO2 (-)
Chlorite
CrO4(2-)
Chromate
Chlorine
Cl-
Ionic Compounds
Contain both (+) cations and (-) anions charged ions. Formed when 1 or more electrons transfer from one neutral atom to another
CN (-)
Cyanide
Cr2O7(2-)
Dichromate
H2PO4 (-)
Dihydrogen phoshate
CH2O
Empirical formula
Fluorine
F-
Empirical
Gives only the relative number of atom Superscripts with smallest whole number ratios
Chemical Formula
Indicates which atoms are found in the molecule In what proportions they are found (ratio)
Salts (NaCl, Mg3N2)
Ionic Compounds
Structural formula
Lines to represent covalent bonds and shows how atoms are connected Does not describe the arrangement in space (not 3D)
Oxygen
O2-
Cations
Metals or polyatomic ions
C6H12O6
Molecular formula
Nitrogen
N3-
Nick the camel ate an inch clam for supper in phoenix
Nick= Nitrate (1 vowel= charge, 3 constants= #'s of oxygen) N1O3 (-1) Camel= Carbonate CO3 (2-) Clam= Chlorate ClO3 (1-) Supper= Sulfate SO4 (2-) Phoenix= Phosphate PO4 (3-)
NO3(-)
Nitrate
NO2(-)
Nitrite
Phosphorus
P3-
ClO4 (-)
Perchlorate
MnO4 (-)
Permanganate
O2 (2-)
Peroxide
PO4 (3-)
Phosphate
Sulfur
S2-
Polyatomic Cations
Use (ium) ending
How do you name formulas that contain water?
Use greek prefixes to indicate number of water molecules 1/2 = hemi 1 = mono 2 = di 3 = tri 4 = tetra 5 = penta 6 = hexa 7 = hepta 8 = octa 9 = nona 10 = deca
