Simple math expressions...

[Mephisto]

For some reason I keep getting different answers with different online calculators I'm using, so I just want a definitive answer from a TI-83 (or something similar) calculator which I would use if I had...

(4.131e-5) / (9.58e-4 * 3.58e-4) = ?
(6.579e-5) / (9.34e-4 * 5.34e-4) = ?
(9.486e-5) / (9.05e-4 * 7.05e-4) = ?
(1.097e-4) / (8.90e-4 * 8.90e-4) = ?

If you're curious, I'm calculating equilibrium constants from my lab.  The most ideal results of these calculations would for these to all be the same (they're the concentrations of all the ions in equilibrium of the 4 different equilibrium systems setup).

[dxoigmn]

Trying to fit data to match what it should theoretically be is really bad science (and should get you in trouble, IMO). The results for each individual equation should be the same among several calculators to the appropriate amount of significant digits (which looks like 3, but I can't be too sure without seeing your lab). I would suggest just marking them down as they are calculated. You can use google to get the values.

[Mephisto]

I'm not trying to match data to what it should be... I simple want the answer to these expressions...sheesh.  The online calculators don't yield the same results as Ti calculators (floating point precision) and thus I really need a Ti calculator for these which have higher precision with floating points.

[dxoigmn]

I'm not trying to match data to what it should be... I simple want the answer to these expressions...sheesh.  The online calculators don't yield the same results as Ti calculators (floating point precision) and thus I really need a Ti calculator for these which have higher precision with floating points.

Well then...straight form my TI-83:

Code Select Expand


(4.131e-5) / (9.58e-4 * 3.58e-4) = -.3689279949
(6.579e-5) / (9.34e-4 * 5.34e-4) = -.3513024166
(9.486e-5) / (9.05e-4 * 7.05e-4) = -.3708069833
(1.097e-4) / (8.90e-4 * 8.90e-4) = .013294199


[Mephisto]

I believe I wrote the expressions wrong.  I meant for the 'e' to be scientific notation, which I believe is a cap 'E.'  ~sorry

But I got the answers I needed, thx anyways:)