Recent content by ajkoer

Yes, I agree with most of your comments. For those interested in more details on this topic, please see the following reference (full paper) at http://www.jim.or.jp/journal/e/pdf3/45/04/1317.pdf . To quote from the abstract: "We developed a chemical model to analyze ionic equilibria in a...

With respect to the solid compound, a burning strip of Mg. Reaction with nitrogen, per Wikipedia (http://en.wikipedia.org/wiki/Magnesium_nitride ) "Magnesium nitride can be produced by heating magnesium metal in a pure nitrogen atmosphere. 3 Mg + N2 → Mg3N2 In fact, when magnesium is burned...

Some definitions first: Solubility is the ratio of the maximum amount of solute to the volume of solvent in which this solute can dissolve. Thus, the Ksp is, in my opinion, a statistically base estimate relating to (that is, function of) a sampling of the maximum amount of solute to the volume...

I disagree with the comment "we don't have a good theory for calculations at high ionic strengths" unless you qualify it as your personal opinion. The theoretical equation and numerical models based thereon (which are non-linear and require interative solutions) to predict the ionic strength of...

A qualitative test for the presence of Barium uses the fact that BaCO3, a slightly soluble salt in water, becomes soluble in dilute acid solutions of HCl, HNO3 and even Acetic acid. Per the current discussion topic, this is effected by the fact that even a largely insoluble salt must...

Solubility is a statistical concept. That is why, upon addition of some HNO3, one can, with work, get some of the BaSO4 to dissolve.

I suspect it was concentrated H2O2. A catalyst triggered decomposition of Hydrogen peroxide can be very violent (even explosive if confined). The products are H2O (steam if hot enough) and O2, basically non-toxic.

Galvanic Corrosion - a contributing factor To quote from Wikipedia on Galvanic Corrosion (Please see http://en.wikipedia.org/wiki/Galvanic_corrosion): "In other cases, such as mixed metals in piping (for example, copper and cast iron), galvanic corrosion will contribute to accelerated...

OK, one way to isolate the MgCl2 is to convert it into the insoluble MgCO3 and treat with Cl2 or HCl to regenerate the MgCl2. The precise preparation is as follows: 1. Add your salts (MgCl2, CaCl2, NaCl, and KCl) to a solution of Selzter water (H2CO3) and ammonia. 2. Heat to just 50 C to...

General test measure: For time accurate to the nearest minute, assume the existence of a perfect random alarming clock. The probability that in any given minute the alarm is correctly alarmed is 1/(24*60). Run simulations where the run length equal to the # of tests on the real alarm clock...

By “highest-level measures” I would assume that all the data is incorporated in the mean/variance estimate. Solutions: Answer 1: Use standard regression theory although the error terms (difference between fitted and observed) is not precisely normal (a mixture of dummy variables...

To determine the statistic significance of the points in space with random error, I would assume a shape, based on prior data examples, and then calculate an estimate of the Standard deviation from the assumed model 'true' points. Note, this is one case where upon selecting a poor model for the...

I agree that Hydrogen is more reactive than Copper. Heat solid CuCl2 (below its temperature of decomposition) and pass H2 gas over it. I would expect: CuCl2 + H2 --> Cu + 2 HCl

Here is a relationship between A = LL' and the diagonal matrix D of eigenvalues of A. Assume there exist a matrix P such that P'P = I and PAP' = D. Then, P(A^2)P' = D^2 or, P(LL'LL')P' = D^2 or, (PL)L'L(PL)' = D^2 Note, (D^-1/2)*(PL)*(L'P')*(D^-1/2) = (D^-1/2)*(PAP')*(D^-1/2) =...

Clearly an example is all matrices for which B = kA, where k is a scalar. Then, the eigenvalues differ by a constant factor and the matrix M diagonalizes both A and B as required.