The Periodic Table

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Mabadai

12:21 AM

hello

3 hours later…

getafix

2:58 AM

Any solid state chemists/crystallographers here? I have some questions about structure factor calculations, and XRD peak assignment.

1 hour later…

Martin - マーチン

4:05 AM

@Loong My thoughts exactly, but I was referring to that question.

Allenph

5:04 AM

Hey all. A while ago I was asking about handling a solution of muriatic acid and H202 used to etch copper from PCBs. Someone suggested that I enclose the acid to avoid fumes rusting my equipment (which happened before) and the acid evaporating leaving a weak etchant. I just neutralized all of my old acid with baking soda and started a smaller batch in a jar that has a rubber ring that clamps down. (The kind used for jam). It appears to be keeping the fumes contained...but when I opened the jar

I got a pretty strong gust if HCL fumes and something precipitating in the top of the jar. Thoughts? I've read that the fumes escape because the HCL provides a nucleation point for water vapor in the air...will the pressure just build until there is no more water?

1 hour later…

Martin - マーチン

6:06 AM

@Loong Now that I see that, it really pains me to say, that I have just one of these papers in front of me. What puzzles me is, it is from 2010 and published in JACS. I know that their staff usually asks for high resolution images. And since I used those programs myself, I know they can produce these images... well, well, we'll never know why...

4 hours later…

orthocresol

10:14 AM

@Loong I might have to pronounce Knoevenagel in front of three Germans later today. This is very helpful.

getafix

11:11 AM

@orthocresol I did the exact same thing about a year ago haha

orthocresol

12:05 PM

Pretty close to one whole year, eh. Time flies...

6 hours later…

Loong

6:21 PM

@orthocresol That's why I also put it in here:

Knoevenagel condensation

The Knoevenagel condensation (pronounced [ˈknøːvənaːɡl̩]) reaction is an organic reaction named after Emil Knoevenagel. It is a modification of the aldol condensation. A Knoevenagel condensation is a nucleophilic addition of an active hydrogen compound to a carbonyl group followed by a dehydration reaction in which a molecule of water is eliminated (hence condensation). The product is often an αβ-unsaturated ketone (a conjugated enone). In this reaction the carbonyl group is an aldehyde or a ketone. The catalyst is usually a weakly basic amine. The active hydrogen component has the form Z–CH2...

Aaron Hall

6:38 PM

If I recall from my chemistry classes, water is a universal solvent, and hotter water will dissolve things faster and can hold more impurities than colder water. Am I correct?

reveals his confirmation bias

@-ping me - I won't be monitoring this...

1 hour later…

Loong

8:13 PM

I was actually working in the laboratory again today. I almost felt sentimental.

1 hour later…

M.A.R.

9:37 PM

@DSVA whoa there, are you insulting the molecule stereotype?

@Loong did it feel like meeting your most hated teacher on the street?

M.A.R.

10:05 PM

-1

Q: Buffer Question

You need to produce a buffer solution that has a pH of 5.27. You already have 2L of 0.01M acetic acid solution. How many grams of sodium acetate salt will you need to add to this solution? The Ka of acetic acid is = 1.6 x10-5 HOAc (acetic acid) H+ + OAc- (acetate) If 0.005moles of NaOH was ...