There are 3 types of compounds that one should know: Type 1, Type 2 and Type 3.
Type 1
Type 1 compounds are ionic. There is a cation (group 1 and 2, Al, Zn, Ag, and Cd on the periodic table)
and there is an anion (non-metal/polyatomic ion).
The first thing you need to do is write the name of the cation. Then, change the ending of the anion to "-ide". For example, oxygen = oxide, sulfur = sulfide, ect.
Never change the name of a polyatomic ion.
Example of a Type 1: potassium + chlorine
K+ Cl- =KCL
=potassium chloride
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Type 2
The most important thing to remember about Type 2 compounds is this: DO NOT TRUST THE PERIODIC TABLE!
Mn SO4 = manganese (II) sulfate
Mn2 (SO4)3 = manganese (III) sulfate
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Type 3
Uses prefixes to tell how many each element there are in the compound. (don't use mono on the first element in the compound)
1: mono
2: di
3: tri
4: tetra
5: penta
6: hexa
7: hepta
8: octa
9: nona
10: deca
Remember to change the ending of the last element to "-ide"
Examples:
H4C2 = tetrahydogren dicarbon
CO =carbon monoixde
P2O4CL3 = diphosphorus tetraoxygen trichloride
Tuesday, December 21, 2010
Chemistry Games
I was online one day looking for some help with the periodic table. Lo and behold, I find a site dedicated to chemistry games that actually help!
Here is the website address: http://www.sheppardsoftware.com/Elementsgames.htm
Here is the website address: http://www.sheppardsoftware.com/Elementsgames.htm
Molecular Formula
Every molecular formula is a whole number multiple of the empirical formula.
In order to find the molecular formula, find the multiplier:
Here is an example on finding the molecular formula:
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I do have one question relating to molecular formula; how can compound be a molecular and empirical formula at the same time:
For example:
Why is the answer E?
In order to find the molecular formula, find the multiplier:
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I do have one question relating to molecular formula; how can compound be a molecular and empirical formula at the same time:
For example:
Why is the answer E?
Empirical Formula
The definition of an empirical formula is to take a molecule and put it into the simplest whole number ratio. Be sure to remember that ionic compounds are usually already in empirical formula.
Here is an example: C2 H6 ----------------> CH3
The 2 IN C2H6 is the molecular formula (tells you what and how many are in a molecule). We'll get to the molecular formula later.
The 1 in CH3 is the empirical formula (simplest whole number ratio).
Here are two more examples to finding the E.F.:
C9H16 ----------> C9H16
C62H4O12 ---------> C31H2O6
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Finding the empirical formula is easy, you just have to follow some steps.
First, go from percent to mass
Second, mass to moles
Third, divide by the smallest
Fourth, multiply until it's whole
Here is an example by using the steps above in order to find the E.F.:
And there is how to solve E.F. in a nutshell!
Here is an example: C2 H6 ----------------> CH3
The 2 IN C2H6 is the molecular formula (tells you what and how many are in a molecule). We'll get to the molecular formula later.
The 1 in CH3 is the empirical formula (simplest whole number ratio).
Here are two more examples to finding the E.F.:
C9H16 ----------> C9H16
C62H4O12 ---------> C31H2O6
************************************************************************
Finding the empirical formula is easy, you just have to follow some steps.
First, go from percent to mass
Second, mass to moles
Third, divide by the smallest
Fourth, multiply until it's whole
Here is an example by using the steps above in order to find the E.F.:
Christmas Tree Story
I was listening to Science Friday on NPR one day and found myself listening to this really cool interview called 'Chemistry Keeps Christmas Tree Alive, For Longer'. The subject of the interview was to explain how and why trees lose their needles. At the Nova Scotia's Christmas Tree Research Center, researchers are trying to find a way to extend the life of Christmas Trees.
Here is the website to listen/read the interview: http://www.npr.org/2010/12/10/131967516/Chemistry-Keeps-Christmas-Trees-Alive-For-Longer
Here is the website to listen/read the interview: http://www.npr.org/2010/12/10/131967516/Chemistry-Keeps-Christmas-Trees-Alive-For-Longer
Wednesday, October 20, 2010
Interesting Story!
I was looking for a cool story that relates to Chemistry, and I do believe I found something! I knew that books tend to spell the older the get, but I never knew why. Thanks to this article in The Naked Scientists called 'Smell Test for Old Books.' As it turns out, the volatile organic compounds that paper releases builds up like acids which increase as the paper gets older and older.
Not only did I find out why older books give off a certain smell, I also found a website that is filled with fun articles!
To read this article in full, here is the URL : http://www.thenakedscientists.com/HTML/content/news/news/1851/
To get to The Naked Scientist main page, here is the URL:http://www.thenakedscientists.com/HTML/content/news/
Not only did I find out why older books give off a certain smell, I also found a website that is filled with fun articles!
To read this article in full, here is the URL : http://www.thenakedscientists.com/HTML/content/news/news/1851/
To get to The Naked Scientist main page, here is the URL:http://www.thenakedscientists.com/HTML/content/news/
Scientific notation and significant figures
Last week my Chemistry class reviewed scientific notation (S.C.) and significant figures (S.F.). I used to think that you could only use scientific notation with whole numbers, but I now know that you can use this notation with decimals as well! Scientific notation makes writing really big or small numbers easy.
Scientific notation
Let's start with whole numbers. An example of a whole number in S.C. looks like this:85000000 = 8.5 x 10^7.
The first thing you need to do is count from the right side until you get to the first number (it takes 7 times to get to the first number, 8)
Next, you put a decimal after the first number and then leave all number behind (unless it's a zero), so it looks like this: 8.5
Then, you add ' x 10' after 8.5, so it looks like this: 8.5 x 10.
Now, remember when you had to count how many times it took to get to the 8? Well, that number (7) is the final part to scientific notation! You simply add ^7 right after the 8.5 x 10, so the finish product looks like this : 8.5 x 10^7.
For finding scientific notation for decimals, you do the same process for finding whole number S.C. The only two differences are that you start from the left side and that the exponent is negative. For example: 0.000253 = 2.35 x 10 ^-4. So, you start on the left side and it take 4 times until the decimal is after the 2. You have a negative exponent because you are coming from the left.
Significant figures
Now, finding significant figures means the numbers that matter in a calculation. To find S.F. is simple, just use the America, Pacific and Atlantic ocean!
The Pacific Ocean is used for decimals, (the P stands for period) and the Atlantic Ocean is used for whole numbers (the A stands for absent a period). The first thing you have to do is figure out if the number is a decimal or whole number.
The example I'll use is 22. This number will be on the Atlantic side, which means you'll have to start on the right side of the number and count the numbers (not including zeros). So, 22 has 2 S.F.
If there is a number like 4572630001, you still start on the right side and since the number 1 is the first number and the zeros come after 1, you will count the zeros as well. So, this number has a total of 10 S.F.
The example I'll use for the Pacific side will be1.085. This number has a total for 4 S.F. To figure out how many S.F. a decimal has, you start on the left side of the number and count. For 1.085, there are 4 numbers, so the S.F. is 4
If there is a number like 0.009, you still start on the left side, but don't count until you get to a number other then 0. This leaves us will 9, meaning that 0.009 only has 1 S.F.
Scientific notation
Let's start with whole numbers. An example of a whole number in S.C. looks like this:85000000 = 8.5 x 10^7.
The first thing you need to do is count from the right side until you get to the first number (it takes 7 times to get to the first number, 8)
Next, you put a decimal after the first number and then leave all number behind (unless it's a zero), so it looks like this: 8.5
Then, you add ' x 10' after 8.5, so it looks like this: 8.5 x 10.
Now, remember when you had to count how many times it took to get to the 8? Well, that number (7) is the final part to scientific notation! You simply add ^7 right after the 8.5 x 10, so the finish product looks like this : 8.5 x 10^7.
For finding scientific notation for decimals, you do the same process for finding whole number S.C. The only two differences are that you start from the left side and that the exponent is negative. For example: 0.000253 = 2.35 x 10 ^-4. So, you start on the left side and it take 4 times until the decimal is after the 2. You have a negative exponent because you are coming from the left.
Significant figures
Now, finding significant figures means the numbers that matter in a calculation. To find S.F. is simple, just use the America, Pacific and Atlantic ocean!
The Pacific Ocean is used for decimals, (the P stands for period) and the Atlantic Ocean is used for whole numbers (the A stands for absent a period). The first thing you have to do is figure out if the number is a decimal or whole number.
The example I'll use is 22. This number will be on the Atlantic side, which means you'll have to start on the right side of the number and count the numbers (not including zeros). So, 22 has 2 S.F.
If there is a number like 4572630001, you still start on the right side and since the number 1 is the first number and the zeros come after 1, you will count the zeros as well. So, this number has a total of 10 S.F.
The example I'll use for the Pacific side will be1.085. This number has a total for 4 S.F. To figure out how many S.F. a decimal has, you start on the left side of the number and count. For 1.085, there are 4 numbers, so the S.F. is 4
If there is a number like 0.009, you still start on the left side, but don't count until you get to a number other then 0. This leaves us will 9, meaning that 0.009 only has 1 S.F.
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