Monthly Archives: November 2012
The name game…
So you want to name a compound or identify a formula huh? Well first we need to know what type of compound we’re talking about (See the rules for determining the type of compound on the previous post).
Here is a quick rundown of the rules for naming Binary Compounds.
Nonmetal + Nonmetal = Molecular Compound
When naming molecular compounds, we use prefixes to identify how many of each type of element are present in the compound.
- Mono * 6. Hexa
- Di 7. Hepta
- Tri 8. Octa
- Tetra 9. Nona
- Penta 10. Deca
*The only time we vary from this is when there is only one of the first type of element we don’t add mono. For example, CO is Carbon monoxide, not Monocarbon monoxide.
The final rule for naming Molecular compounds is that the second element, when it is a nonmetal, the ending is changed to the suffix “-ide”. For example, Sulfur would be sulfide.
So for example, P4O10 would be Tetraphosphorus Decaoxide
Metal + Nonmetal = Ionic Compound
To name an ionic compound, we do not need to use prefixes to name our compounds. Instead, we have to identify the charge of the elements we’re working with.
If the element is a metal, it will is a Cation (+). If the element is a nonmetal it is an Anion (-).
The charge is usually written on the periodic table, but it can also be deduced from the placement of the element on the periodic table. Alkali Metals are all +1, Alkaline Earth Metals are all +2, and Group 3B is +3. Likewise the Halogen group (7A) is -1, the Oxygen group (6A) is -2, and the Nitrogen group (5A) is -3.
After you determine the charge of the elements, you then find the “Common Charge” in order to make the compound balanced (same number of +/- charges on each side). Lets take Magnesium fluoride for example.
Mg has a charge of +2; while F has a charge of -1. In order to make the charges balance, we can add atoms to one side or the other. In this case, we need another F -1 in order to make the compound balance. So the common charge of Magnesium fluoride is ±2, and the formula would be written MgF2
Hello. My name is Boron Trichloride.
Well, if your initials were BCl3 than it would be at least.
Today we begin Unit 5: Naming, and there is some good news and bad news to go along with that.
The good news is that there is not a lot of math, no formulas, no Avogadro’s number.
The bad news is that there are some tricky rules to what to name a compound when.
So, today we’ll be introduced to how to identify a Binary Compound. A Binary compound is any compound with two elements. When the second element is a Nonmetal, we replace the ending of the element with “-ide” (Like Carbon Dioxide). There are three types of Binary Compounds.
- Molecular Compound → Nonmetal + Nonmetal
- Ionic Compounds → Metal + Nonmetal
- Binary Acids → Hydrogen + Nonmetal (The name begins with “Hydro” and the “-ide” at the end of the nonmetal is replaced with an “-ic”
Today we’ll be focusing on identifying the elements, determining if they are a metal (M) or nonmetal (NM), and identifying the type of compound. Here are a few examples:
Formula 1st Symbol 2nd Symbol Type of Compound
ZnO Zn (M) O (NM) Ionic Compound
BCl3 B (NM) Cl (NM) Molecular Compound
HBr H (Hydro) Br (NM) Binary Acid
Review Questions! Quest Tomorrow!
If the form below does not load, you can view the online review questions by clicking here
“Quest” moved to Tuesday
Mole “Quest” Friday
We’ll continue working on our atom-mole-molecule calculations today. The goal is to have this done by Thursday to have time to prep for the “quest” on Friday. (It’s bigger than a quiz, but smaller than a test… it’s a quest, get it?)
These calculations can take time to do so be patient and be persistent. Check your work on the Semester 1 Docs page!
It’s Molection Day!
Okay seriously though this photo reminds us of two major events occurring today:
- It’s Election Day! It does not matter who you vote for, only that you vote! Mrs. Bassinger here and the rest of the social studies department will be putting on a mock-election. What a great way to exercise some good old American Patriotism. ‘Merica!
- Our Moles are due this week and some of them have already been turned in. The “Voting Mole” pictured here was a very clever idea. Check the “Photos” page for more of our creative creations!
Atoms – Moles- Molecules
This week we take the next step in the evolution of mole conversions. So far we have worked on one side of our graphic organizer or the other.
- Mass of Atoms – Moles of Atoms – Atoms
- Mass of Molecules – Moles of Molecules – Molecules
This week we connect the dots. This week you’ll be given a mass of molecules and work across the graphic organizer to get to mass of each atom that makes the molecule. ( For example: Mass P2O5 Molecules = Mass of P atoms + Mass of O atoms )
You’ll need to follow dome simple steps, which you have learned how to do in past lessons, in order to come up with your final figures.
- Calculate Molar Mass of the molecule (Multiply atomic masses by subscripts; add)
- Calculate the moles of the molecule (Given / molar mass)
- Calculate the moles of one of the atoms that make up the molecule (moles of molecules x subscript of atom)
- Calculate the mass of those atoms (moles of atom x atomic mass)
- Calculate the moles of the other atoms that make up the molecule (moles of molecules x subscript of atom)
- Calculate the mass of those atoms (moles of atom x atomic mass)
- Check your results with the law of conservation of mass (Mass of Molecules = Mass of atoms + Mass of atoms)
The ol’ Switcheroo
There is a handout you will need for today… no matter who may be teaching the class.
There is also a voicethread on Factor Labeling with Moles that goes step-by-step through the process.
Enjoy All-Saints-Day and the ol’ SWITCHEROO!
Oh yeah… and the Quiz is MOVED TO TOMORROW!