foxsciencecentre.weebly.comfoxsciencecentre.weebly.com/uploads/1/2/6/9/12697834/… · Web...
Transcript of foxsciencecentre.weebly.comfoxsciencecentre.weebly.com/uploads/1/2/6/9/12697834/… · Web...
Science 10: 4.2 Names and Formulas of Compounds
Text: Chapter 4, pages 184-201
Part A: Chemical Name of Ionic Compounds
-What is an ionic compound?
_____________________________________________________________________________________
-The International Union of Pure and Applied Chemistry regulates the naming of compounds. For example, the chemical name “Potassium Iodide” is governed by the following rules:
a) First Word: Positive ion (metal)
b) Second Word: Negative ion (non-metal)
c) Second Word Ending: Negative ions always end in “ide”
-Try using these rules on the examples below:
Rule MgO Ca3N2
First Word
Second Word Ending
Compound Name
Part B: Chemical Formula of Ionic Compounds
-Examine the chemical formula right. What does it reveal about the ionic compound?
________________________________________________________________
________________________________________________________________
Science 10: 4.2 Notes Page 1
-There are several steps necessary to create formulas for ionic compounds:
-Try using these rules on the following examples:
Steps Beryllium Sulphide Aluminum Oxide1. Ion and Charge
2. Balance Charges
3. Ration
4. Chemical Formula
Part C: Compounds Containing a Multivalent Metal
-What is a multivalent metal?
___________________________________________________________________
___________________________________________________________________
-To show the difference between two ions from the same multivalent metal roman numerals are used to show the ion charge. For example:
a) Nickel (II) Chloride is NiCl2
b) Nickel (III) Chloride is NiCl3
-What do Roman numerals reveal about a metal ion?
___________________________________________________________________
Science 10: 4.2 Notes Page 2
Cross-Over Method
Atom: Al F
Valence: +3 -1
Formula: AlF3
Part D: Steps for Writing Formulas of Ionic Compounds Containing a Multivalent Metal
-Use these steps to try the following examples.
Steps Iron (III) Bromide Lead (IV) Oxide1. Ion and Charge
2. Balanced Charges
3. Ration
4. Formula
Science 10: 4.2 Notes Page 3
Part E: Steps for Naming Ionic Compounds that Contain a Multivalent Metal
-Use these steps to try the following examples.
Steps CoCl2 Ni2O3
1. I.D. Metal
2. Identify the Ions
3. Ion Ratios
Science 10: 4.2 Notes Page 4
4. Negative Ion Charge
5. Balance Positive and Negative Charges
6. Compound Name
Part F: Polyatomic Ions
-A polyatomic ion is made of more than one type of atom joined by covalent bonds. See the Lewis Diagram of Calcium Carbonate above.
-The table below lists the names of polyatomic ions. You do not need to memorize these!
-Below are the steps for naming an ion containing a polyatomic
ion:
Steps Cu2SO4 NH4CH3COO NaOH (NH4)2CO3
1. Identify Positive Ion, check if multivalent and write name2. Identify Negative Ion and write its name3. Write the compound name
-Below are the steps for writing the formula of compounds with polyatomic ions.
Science 10: 4.2 Notes Page 5
Steps Potassium Permanganate
Lead (II) Perchlorate
1
2
3.
4.
5.
Part G: Names and Formulas of Covalent Compounds
-The chemical formula of covalent compounds shows the number of atoms present.
-How many atoms of each element are present in H2O2(Hydrogen Peroxide)? Two H and two O.
-How would the formula H2O2 be treated if it represented an ionic bond?
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
Part H: Naming Binary Covalent Compounds
-A binary covalent compound contains two non-metals joined by one or more covalent bonds.
-As these compounds can consist of two or many atoms, prefixes are used to show the number of atoms of each element present.
-Below are the steps for naming binary covalent compounds that do not contain hydrogen:
Steps CO N2O3 Cl2O1. Name the first element
2. Name the
Science 10: 4.2 Notes Page 6
Number Prefix1
2
3
4
5
6
7
8
9
10
second element and change the ending to ide3. Add the appropriate prefix
*Exceptions to Step 3:-No prefix for the first element if there is only one atom-Prefix mono becomes mon if it is placed before oxide
-The naming of covalent compounds containing hydrogen will be covered in Chapter 5.
Part I: Formulas for Binary Covalent Compounds
Steps Chlorine Monofluoride
Dinitrogen Tetraoxide
Sulphur Dioxide
Selenium Difluoride
1. Identify the first non-metal and use a subscript
to show the number of atoms
1. Identify the second non-metal and use a subscript
to show the number of atoms
3. Write the formula
*Refer to text pages 196 and 197 for hints in naming ionic and covalent compounds
Science 10: 4.2 Notes Page 7