Recent content by JohnRC

It is a matter of symmetry. One way to look at it is as follows: the molecule has a centre of symmetry. A dipole is like a vector that points in a single direction. But you cannot have a dipole with this symmetry, because if you inverted the molecule through the centre of symmetry, the molecule...

Take an oxygen atom with 6 valence electrons. Remove one to make O+ with 5 valence electrons. Now make covalent bonds with three hydrogen atoms each donating one electron into the bonding, and you have H3O+, with 8 valence electrons around the oxygen, when you count the three that are shared...

If you start out with y mol of phosgene, then what the balanced equation tells you is that when x mol of it react to produce carbon monoxide and chlorine, the number of mole of the three substances will be y – x , x , and x respectively. That is not a 1:1:1 ratio!

Because the stoichiometric ratios are not 1:1:1. If they were, the equilibrium constant would be equal to 1/(partial pressure of any of the three gases) -- and that could not be a constant! You need to think differently about what the meaning of the stoichiometric equation might be.

not molality (m) but molarity (M). There is a subtle, but important difference. And I do not think that that is where your problem lies because normality (N) is a "drop in" substitute for molarity (M) for monofunctional reagents. "Equivalent weights" and "Normality" are no longer used by...

Zinc oxide is produced in nanoscale particles for use in some cosmetic products and/or sunscreens. Whether details of particle size control are available in the open literature rather than as commercial secrets I do not know -- you would have to research that for yourself. The secret of making...

Experimentation in this area can be enormously difficult. In the ideal situation adsorption should simply increase with time, and the equilibrium will be a practical compromise where the upward trend in adsorption (downward trend in residue analysis) falls below an estimated error scatter. So...

CO has the strongest bond of any known (or possible) molecular compound -- stronger even than nitrogen gas. Breaking it into elements requires extreme temperatures. I am a little surprised that it can be achieved with temperatures as low as 2000 K. The molecule can be broken down by...

DrDu is quite right. Here is an interesting case for the original poster to consider: Cobalt and nickel have near identical molar masses, near identical atom sizes, and exactly identical metal densities. But cobalt packs as hexagonal close-packed, while nickel packs as cubic close-packed (i.e...

There are a lot of complicated issues in the chlorine/oxygen competition at an anode. Two of the main considerations are (1) that an electrolyte is not always at 1 M activity (standard state), and any departure from this affects the potential value (Nernst equation) (2) that chloride ion is...

It is all a matter of energy. The bond may be regarded as very polar covalent or ionic, for whatever purpose you might want. Nature does not know about chemical bonds! However, if you try to dissociate gaseous NaCl, the lowest energy pathway is to Na• + Cl• rather than Na+ + Cl– Because the...

ΔH does not have to be negative for a spontaneous process. Solution of ammonium nitrate is spontaneous, and that is a process that takes in a lot of heat from its surroundings, Many processes are endothermic and spontaneous.

I am no economist, but I strongly suspect that Paul's monthly allowance is irrelevant, and that you just have to concentrate on the utility that grandma's gift might bring if in cash form.

From Einstein McFly: But in the chemist's story about bonding, the sulfur 3d orbitals are neither too high in energy nor too large and diffuse to participate in the bonding in this compound, because inductive withdrawal of electron density from sulfur to fluorine in this compound will cause...

With liquid/liquid extraction, you get a partitioning constant -- at equilibrium, the activity (concentration) of the analyte in the two solvents is in a constant ratio (partition coefficient) at a particular temperature. For example a(Iodine in chloroform at 25°C)/a(iodine in water at 25°C)...