Download Mini-project with naming rules

Chemistry Mini-Project
Name___________________________________
Given a set of 3–5 elements, write the names and formulas of several ways that the elements might combine to make
compounds and/or polyatomic ions.
Select two compounds to explain, orally and in writing, how and why the compound can be made from a given set of
elements. (C2.F, C2.I; C.7A, C7.B) 5B, 5F
Handout: Element Cards (1 per student)
2. Students will use the elements on their cards to create at least one of each of the compounds in each category
listed below, recording the compounds on the mini-project paper. Explain, in writing, how and why each compound
can be made from your given elements.
3. Your list of compounds should include the following:
a. ionic compound without a polyatomic ion
Ionic compounds are formed when a metal (which only has 1,2, 3, or occasionally 4 valence electrons) gives up those
valence electrons and becomes a positive cation. Oxidation numbers: group 1 is +1, group 2 is +2, Group 3 is +3, and the
transition elements have varying valence electrons indicated by a roman numeral (I, II, III, IV).
The metal cation combines with a nonmetal anion which has gained electrons to fill its valence shell. (Remember that
their valence shells are close to full- they want 8.) Elements in group 15 will take 3 electrons and have an oxidation
number of -3, elements in group 16 will take 2 electrons and have an oxidation number of -2, elements in group 17 will
take 1 electrons and have an oxidation number of -1.
These ions combine because opposite charges attract. The oxidation numbers must ‘cancel out’ so that the compound is
neutral.
Use the name of the first element when naming ionic compounds that are made up of only 2 elements. The second
element name will be the “ide” name. (Oxide, fluoride, chloride, bromide, selenide, nitride, phosphide, iodide, hydride)
Examples: Na+1 and Cl -1 combine to form NaCl sodium chloride:
Mg+2 and F-1 combine to form MgF2 magnesium fluoride (we need 2 of the F-1 so that the charge is
-2 and cancels the +2 charge on Mg+2)
b. ionic compound with a polyatomic ion
These compounds are formed in the same way that the binary ionic compounds form- except we use a polyatomic ion
instead of a single element ion.
A metal cation will join a polyatomic anion (OH-, CN-, HSO4-, PO4 -3)
Examples: Mg+2 and CO3 -2 will combine to form MgCO3 magnesium carbonate
Ca +2 and PO4 -3 will combine to form Ca3(PO4)2 calcium phosphate- We must make the charges equal
and opposite so that they will cancel. Three Ca+2 ions will have a charge of +6. Two PO4 -2 ions will have a charge of -6, so
the charges will cancel and the compound is neutral.
c. covalent compound
Covalent compounds are formed when nonmetals share electrons to become more stable.
Name the first element. Name the second element using the ‘ide’ form.
Use prefixes
Do not use mono on the first element
Use ‘o’ in lace of ‘oo’ or ‘oa’
Examples: CO- carbon monoxide: CCl4- carbon tetrachloride: N2O- dinitrogen oxide
d. acid – use the rules for naming acidsAll binary (made of 2 elements) acids are named the same way:
1-the prefix "hydro" is used.
2-the root of the anion is used.
3-the suffix "ic" is used.
4-the word "acid" is used as the second word in the name.
The name for HCl is hydrochloric acid. HF- hydrofluoric acid, HBr- hydrobromic acid, HI- hydroiodic acid, and H2Shydrosulfuric acid. HCN also follows this rule and is named hydrocyanic acid.
Ternary Acids
You MUST recognize the polyatomic ion in the formula. There is no other way to figure out the name. If you don't
recognize the polyatomic, then you need to review the list of polyatomic ions.
HClO2 has the ClO2¯ polyatomic ion in it. The name of this ion is chlorite.
Since the "ite" suffix is used, it gets changed to "ous."
(‘ite’ becomes ‘ous’ lighthouse)
The name of HClO2 is chlorous acid.
HClO3 has the ClO3¯ polyatomic ion and its name is chlorate. Any time you know the "ate" ending is used on the
polyatomic, you use "ic" when you write the corresponding acid formula. (if you ‘ate’ something bad you would say ‘ic’)
The name of HClO3 is chloric acid.
1. recognize when a polyatomic is present and
2. know its name.
Only then can you know to change the "ite" suffix to "ous" and the "ate" suffix to "ic" when it is an acid.
e. base
Include the OH- or the NH3+
NaOH is sodium hydroxide
KOH is potassium hydroxide
Ca(OH)2 is calcium hydroxide (we must have 2 of the OH- ions to cancel the Mg charge of +2)
NH4OH is ammonium hydroxide
3. You may use your notes and other reference materials for this activity- if your element card does not include
Hydrogen, you may add Hydrogen to the elements.