Natural Science Forum / Chemistry / General Chemistry / July 2004

If anyone could help me to solve this I would be glad:
A buffer was prepared by dissolving 3.71 g of citric acid (triprotic) and
2.91 g KOH in water ad diluting to a final volume 250 mL. What is the pH of
this buffer ? Citric acid pKa1 = 3.14, pKa2 = 4.77, pKa3 = 6.39.

I would like to know if posters on these scientific newsgroups can share
any FTP site(s), or HTTP sites linking to FTP or other protected sites,
including log-in names and passwords, from which chemistry and chemical
engineering and related e-books, publications and programs (not

Question:
What is the easiest and effective method of doping fused silica with
sodium in the lab. And for that matter, how does anyone dope fused
silica with any other material like Titanium or OH, etc.

meat rotted inside a refrigerator.
It still stinks after the interior has been washed.
Maybe some sulphides have diffused into the plastic?
Anyhow, is there a reasonable way to destroy whatever's causing the odor?

?

I'm using spectrophotometric analysis to determine the equilibrium
constant of the following reaction for a high school chemistry
assessment.
Fe^(3+) + HSCN <--> FeSCN^(2+) + H^+

I have purchased some capsules sold as a dietary supplement and
labelled `RxOmega-3 Factors'.  According to the label, each gelatin
capsule contains 1 g of fish oil concentrate, derived from anchovies,
sardines, and mackerel, and containing 400 mg of EPA and 200 mg of

Common wisdom is that deep-cycle lead acid batteries should be fully
recharged following a discharge.
Why is this so?
The question is prompted by the fact that getting the final few

I have a piece of blue plastic, called "machinable wax" which looks and
feels like HDPE, and which can be machined very easily (drilling, milling,
sawing etc)
Its melting point is about 100 °C, and the melt viscosity is very low (a bit

Anyone know where I can get some sheep milk protein standards for
quantitative HPLC work ? Alpha, beta and kappa caseins and the
lactoglobulins as separate standards much prefered.
Any pointers most welcome.

I would like to know if posters on these scientific newsgroups can share
any FTP site(s), or HTTP sites linking to FTP or other protected sites,
including log-in names and passwords, from which chemistry and chemical
engineering and related e-books, publications and programs (not

Hi guys, I am not a chemist but I would like to know something
which you chemists may be able to help me with.
Does sodium laureth sulfate have any properties which act as a
water softener?

Now that NiCd or NiMH systems are not that much more expensive, and last
hundreds of times longer, why do they still make Rechargeable Alkaline
Batteries?

In our lab we run a mercury diffusion pump for drying samples for
elemental analysis.  We have an Edwards spark tester that checks for
vacuum.  We are used to seeing a bright purple discharge on which we
take to mean a good vacuum.  However are we correct? Should we be see

Our lab bought a freeze dryer system second hand (ModulyoD), complete
with a vacuum pump (VLP200)and oil recirculation filter (VPOF110) --
all components are from Savant(Thermo).
First, I am searching for documentation (operation and maintenance) on