briman27
Titans Fan
join:2004-01-25
Stratford, NJ
| Math Problem - Cramer's Rule
I have to do this problem for Math class. I don't have any clue on how to do it. We got assigned a set of 5 problems yesterday that are due on Wednesday, and I got all of them done already except this one. Here is the problem.
The atomic weights of three compounds are shown.
(Compound/Forumla/Atomic Weight)
Tetrasulphur tetranitride/S4N4/184
Sulphur hexaflouride/SF6/146
Dinitrogen tetraflouride/N2F4/104
Use a linear system and Cramer's rule to find the atomic weights of sulphur (S), nitrogen (N), and flourine (F).
Any ideas? I have to show my work, so I have to use Cramer's rule to solve this problem.
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LBDSL
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Auburn Hills, MI | I would be willing to bet your teacher would be happy to point you in the right direction.
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ArgyleDSL
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join:2002-07-04
Flushing, NY | reply to briman27
Set up 3 algebraic equations for each one. Then apply Cramers rule to solve them all three. |
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briman27
Titans Fan
join:2004-01-25
Stratford, NJ
| said by ArgyleDSL  :Set up 3 algebraic equations for each one. Then apply Cramers rule to solve them all three. Yes I figured I had to set up 3 algebraic equations, but I don't know what to make for the equations. Once I figure out how to make the equations it's simple. I just have no idea what the equations would be.
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MrFixitSC
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join:2000-12-01
Moncks Corner, SC | reply to briman27
Suggestions on how to proceed are all you'll get here, any "overly helpful" solutions or outright answers will be deleted immediately and likely cause the entire thread to disappear.. |
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whizkid3
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join:2002-02-21
Queens, NY
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2 edits | reply to briman27
It seems like you need more help with algebra, than with Cramer's rule. Granted, though, setting these up in algerbraic form is difficult. However, it is what separates the men from the boys.
Hint: the formlas are in your first post; you even use the word 'Formula' in your post. The only real question is what to set them equal to.
Realize, of course, that you have to show your work, because the answer to the question, is not the three answers. The real answer, is to show that you can do this type of problem.
I just solved it, and the answers are right. |
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MagMan
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Westlake, OH
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| reply to briman27
I have a solution.  |
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BurntCricket
Gotta Do What Ya Gotta Do
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Here
clubs: | MagMan you are a bad man  |
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mobius6
join:2002-12-02
Quantico, VA
1 edit | reply to briman27
I guess the first question is if you understand what the chemical formula stands for. For example, Tetrasulphur Tetranitride has 4 Sulphurs and 4 Nitrogens, and when combined has an atomic weight of 184.
Once that is understood, it is easy to see how to build your system of algebraic equations.
Hope this helps.
Also, the answers are good to go. |
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clank
join:2005-07-04
spain
| reply to briman27
from Weisstein. Concise encyclopedia of mathematics, |
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ArgyleDSL
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Flushing, NY | yup - follow clank's post example |
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briman27
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join:2004-01-25
Stratford, NJ
| reply to mobius6
said by mobius6 :I guess the first question is if you understand what the chemical formula stands for. For example, Tetrasulphur Tetranitride has 4 Sulphurs and 4 Nitrogens, and when combined has an atomic weight of 184. Once that is understood, it is easy to see how to build your system of algebraic equations. That's all I needed. Now I understand exactly how to do it. It's more the science part that threw me off because I didn't know what to do with the chemical forumlas. The math part is simple. I'll do the problem on Monday because who does math on the weekend?
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whizkid3
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join:2002-02-21
Queens, NY | reply to briman27
Once you've finished, you can check your work. Just look at a periodic table of elements. |
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mobius6
join:2002-12-02
Quantico, VA | reply to briman27
I figured that was the hold up.
Math, weekend? Not if I can help it. |
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briman27
Titans Fan
join:2004-01-25
Stratford, NJ | reply to briman27
I just did the problem. I know I got the correct answers because I checked on the Periodic Table and they matched up with my answers. Thanks for the help.
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whizkid3
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join:2002-02-21
Queens, NY
·Earthlink Cable Mo..
| reply to briman27
Here's my solution. Note that I didn't use matrices with Cramer's rule, as I was too lazy - just algebra:
(Compound/Forumla/Atomic Weight)
Tetrasulphur tetranitride/S4N4/184
Sulphur hexaflouride/SF6/146
Dinitrogen tetraflouride/N2F4/104
Use a linear system and Cramer's rule to find the atomic weights of sulphur (S), nitrogen (N), and flourine (F).
4S + 4N =184
S + 6F = 146
2N + 4F = 104
S = 46 - N
46 - N + 6F = 146
N = -100 + 6F
4F = 104 - 2(- 100 + 6F)
4F = 104 +200 - 12F = 304 - 12F
F = 76 - 3F
4F = 76
F = 19
N = -100 +6(19)
N = 14
S = 46 - N = 46 - 14
S = 32 |
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briman27
Titans Fan
join:2004-01-25
Stratford, NJ
| said by whizkid3 :Here's my solution. Note that I didn't use matrices with Cramer's rule, as I was too lazy - just algebra: (Compound/Forumla/Atomic Weight) Tetrasulphur tetranitride/S4N4/184 Sulphur hexaflouride/SF6/146 Dinitrogen tetraflouride/N2F4/104 Use a linear system and Cramer's rule to find the atomic weights of sulphur (S), nitrogen (N), and flourine (F). 4S + 4N =184 S + 6F = 146 2N + 4F = 104 S = 46 - N 46 - N + 6F = 146 N = -100 + 6F 4F = 104 - 2(- 100 + 6F) 4F = 104 +200 - 12F = 304 - 12F F = 76 - 3F 4F = 76 F = 19 N = -100 +6(19) N = 14 S = 46 - N = 46 - 14 S = 32 I set up the same 3 equations and then used matrices and Cramer's Rule. I just plugged the matrices into a graphing calculator and came up with the answer because finding the determinant of each matrix can take a while.
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whizkid3
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join:2002-02-21
Queens, NY | reply to briman27
Just make sure you know how to do it.  |
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