Chapter 5: Ionic and Covalent Compounds Flashcards
Lewis Structure
dots that represent valence electrons (8 is a perfect shell). The dots must go in a circle and must have all paired up before you put 2 in the same orbital.
Ionic Compounds
Normally between a metal and nonmetal; must include ions. In ionic compounds, atoms give up and accept electrons and their magnetism holds them together.
Lattice Energy
amount of energy required to break apart an ionic solid and convert its component atoms into gaseous ions. This decreases when ions differ more in size because they cannot be packed as tightly.
Naming (Ionic) Cations
use the element’s name and add the word ion. (ex: Ca2+ is calcium ion and Al3+ is aluminum ion)
Naming (Ionic) Monoatomic Anions
use element’s prefix and add -ide. (ex: O2- is oxide and F- is fluoride.)
Naming Ionic Compounds
metal normally goes first. Use metal’s name and then for the second atom use its prefix and add -ide. (ex: K2O is potassium oxide, MgCl2 is magnesium chloride.)
Covalent Compounds
indicates they are all neutral atoms, usually between 2 nonmetals. Covalent compounds have a bond due to sharing electrons
Law of Definite proportions
compounds always have a fixed, whole-number ratio.
Homo and Heteronuclear
Homonuclear molecules are only composed of 1 type of element. Hetero are composed of more than one
7 Homonuclear diatomic molecules
“have no fear of ice-cold beer” H, N, F, O, I, Cl, Br
empirical formula
shows relative number of atoms of each element in the compound. (ratios)
molecular formula
shows the actual number of atoms in the compound “actual formula”
structural formula
shows actual number of each element AND their connectivity (image)
Naming Covalent (molecular) Compounds
first identify that you have 2 nonmetals. name exactly like ionic compounds, but add a prefix for the number of atoms. (dinitrogen pentoxide, carbon monoxide)
prefix for 1
mono-
prefix for 2
di-
prefix for 3
tri-
prefix for 4
tetra-
prefix for 5
penta-
prefix for 6
hexa-
prefix for 7
hepta-
prefix for 8
octa-
prefix for 9
nona-
prefix for 10
deca-
what is an acid
a substance that produces hydrogen ions when dissolved in water.
naming simple acids
use the root of the first element and change the second atom’s ending to -ic and add acid. (ex: HF is hydrofluoric acid, HI is hydroiodic acid.)
how to tell if a compound is an acid
if a substance starts with a positive hydrogen ion
what are oxoanions
polyatomic anions that contain one or more oxygen atoms and one atom in the “central atom” of another element. (ex: ClO3, NO3, SO4)
naming oxoanions rules
- ion with one more O atom than the -ate atom is called per…ate ion. (ex: ClO3 is the chlorate ion, so ClO4 is perchlorate ion
- ion with one less O atom than the -ate anion is called -ite ion. (ClO2 is chlorite ion)
- ion with 2 fewer O atoms than -ate is called the hypo…ite ion. (ex: ClO is hypochlorite ion)
oxoacids and naming
acids that when dissolved in water, produce hydrogen ions and oxoanions. (HNO3, H2SO4)
- an acid based on an -ate ion is called -ic, so a HClO3 is chloric acid
- an acid based on an -ite ion is -ous acid, so HClO2 is chlorous acid
- prefixes in oxoanions are retained, so HClO4 is perchloric acid and HClO is hypochlorous acid
phosphate
PO4
chlorate
ClO3
sulfate
SO4
nitrate
NO3
