MIDTERM STUDY (unit 6) Flashcards
Ionic Compounds:
Compounds that are bonded through an electrostatic of oppositely charge ions
How are ions formed?
by loss or gaining of e-
What do ionic formulas consist of?
of a metal and nonmetal or metal and polyatomic ion
Two types of ions:
Cations and Anions
Cations:
positive ion
Anion:
negative ion
Formula Unit:
simplest whole # ratio of the compounds cations to anions
Metals tend to_______ electrons, and nonmetals tend to_________ electrons
lose and gain
Metals form____ and nonmetals form_____
Cations and anions
Ionic bond:
the strong electrostatic force of attraction that holds oppositely charged ions together in a compound
Why do atoms form compounds?
- to gain stability
- to reduce potential energy
Ionic formulas must have a…
net charge of zero -stable-
Binary:
only two elements
ionic:
opposite charged ions (metals and nonmetals)
Monatomic ions:
one element ion
ternary:
an ionic compound w/ more than two elements present
+ will have a polyatomic ion present
Naming Binary Ionic Compounds:
*metal and nonmetal
-cation (metal) goes first
- anion (nonmetal) goes second w/ “ide” ending
ex. LiBr -> lithium bromide
Naming ternary Ionic Compounds:
*metal and polyatomic ion
- cation (metal) goes first
- anion (nonmetal) goes second w/ polyatomic ion name
One polyatomic cation to know:
NH 4 +1
+ all other polyatomic ions will be negative
What method do you use for writing formulas for both Binary Ionic Compounds and ternary Ionc compounds
Cross-over method
When do you use Roman Numerals:
when metals have more than one charge so we have to identify which ion is in the compound
What metals with more than one charge use Roman numerals?
transition metals and p-block metals
What are the two types of acids?
Binary acids and oxyacid
Binary acid:
an acid that contains only two diff elements
- first element will always be hydrogen
- second element will be a nonmetal
Oxyacid:
an acid that contains hydrogen and an oxyanion
Oxyanion:
a polyatomic anion that contains oxygen
ex. NO
Writing formulas for Binary Acid and Oxyacids:
use cross-over method
Naming Binary Acids:
- name of binary acid ALWAYS begins w/ prefix hydro-
- the root of second element name follows prefix
- name ends with suffix –ic followed by word acid
ex. HF -> hydrofluoric acid
Naming Oxyacids:
the name for the oxyacid is based on the name of the polyatomic ion contained in the acid
- the prefix hydro– is NEVER used in naming them
ex.
HNO3
anion = nitrate (NO3-)
name: nitric acid
(in oxyacids) change –ate to
–ic
(in oxyacids) change –ite to
-ous
Hydrates:
contain a certain # of water molecules w/ each formula unit
+ part of crystal structure of the ionic compound
Naming Hydrates:
- name ionic formula 1st
ex. CoCI2 -> cobalt (II) chloride - name water molecule using numerical prefixes with root “hydrate”
ex. hexahydrate
-» cobalt (II) chloride hexahydrate
Writing formulas for Hydrates:
- write formula for ionic compound
- separate hydrate with a “dot”
- write prefix # and add H2O
molecular compound:
formed between a nonmetal and another nonmetal which are held together by a covalent bond (sharing e- ) – forms one molecule
How do we recognize the molecular compound?
the compound will be between two nonmetals
In a molecular compound, which element goes first?
the least electronegative
(farthest to left)
Naming molecular compounds:
-Name first element
- Name second element
use root of element + –ide suffix
–> ALWAYS get a prefix
ex. CO = carbon monoxide
Writing formulas for molecular compounds:
write element symbols down in order
ex. dinitrogen tetroxide = N2O4
