Recent content by ldc3

A split beam would automatically subtract the absorbance of the reference from the absorbance of the unknown and matched cuvettes would be necessary. Most spectrophotometer made now are single beam instruments with processor controls which will subtract the blank spectrum from the sample...

I think that you missed a very important bit of information. Complete Combustion: 67%, propane is burned to CO2 and H2O Incomplete Combustion: 18%, propane is burned to CO and H2O This only accounts for 85% of the propane, so your calculations exclude the oxygen used in 15% of the...

I think you have the mol ratio wrong, but at least you have the correct limiting reagent. The next equation is definitely incorrect, the units don't work out properly. You want the following general equations: Moles of product = Moles of reactant X Rproduct / Rreactant where R is the...

If you took the hydrogen from the oxygen and another hydrogen from a non-adjacent carbon atom, you would then need to connect the oxygen to something and the carbon to something. Also, taking a hydrogen from non-adjacent carbon takes more energy since the oxygen (without a hydrogen) transfers...

Or is it that the transmittance is non-linear? Obviously, one of them is.

The absorption is non-linear. Absorption = -log (Transmittance% / 100) Here is a table of equal values http://www.fruitsmart.com/PDFs/TechnicalForms/AbsorbTxConv.pdf

Although the absorbance is the amount of light absorbed by the solution, we can only measure the amount of light that passes through the solution. The scale of the absorbance is set so that 1% transmittance is 1. Values greater than 1 are possible, but rather difficult to accurately determine.

It doesn't have a charge. See http://www.webelements.com/compounds/antimony/antimony_pentafluoride.html

It looks like I will need to narrow my scan window and decrease the slit width to see if there are any differences. Thank you.

I scanned 2 different compounds (Glucosamine HCl and Glucosamine Sulfate 2KCl) using an FTIR with ATR and their spectra were identical :confused:. Where would the peaks of a sulfate group appear in the IR?

OK so I overestimated the size of a massive star. It's just that when you see Betelgeuse pictured beside our sun (and it looks about 1000000 times larger, one assumes it has 1000000 times the mass as well. "A radius of 5.5 AU is roughly 1,180 times the radius of the Sun—a sphere so huge that it...

I have no problem with description of a small star's formation by gas and dust accretion. The problem I have is with a massive star. When enough material has accumulated to start the fusion of the star, a stellar wind will start and will clear away the gas and dust nearby. A heavier star would...

I've just watched the Extreme Stars program in How the Universe Works and it states that when a massive star starts to make iron, the fusion is quenched and the core collapses. From the program, it sounds like the process is fast and will happen when a few grams of iron is formed. I find this...