The concentration of A is going to depend on the rates of all of the reactions that involve A. In your reversible case, A is used up by both the k1 and k3 reactions, and produced by both the k2 and k4 reactions.
d[A]/dt = -k1[A] + k2[B] - k3[A] + k4[C]
Similarly, the concentration of B will...
I'll try to answer the first part of your post. The pairing of electrons with opposite spin in an orbital has an energy cost associated with it This explains why we see half-filled shells before the system pairs electrons in an orbital (and explains the discontinuities in the ionization...
Magnesium is fairly reducing and so, depending on conditions (condentration, temperature) the acid would be reduced to form dihydrogen.
Mg --> Mg2+ + 2 e- E = 2.37 V
2H+ + 2e- --> H2 E = 0.0 V
Remember that pKa is measuring a thermodynamic quantity (the equilibrium constant of the acid dissociation reaction). If we add negative charges to the histidine environment we stabilize the protonated form relative to the deprotonated form and so the pKa increases (the equilibrium favours the...
If the vibrational mode doesn't involve a change in dipole moment it will not be observed in the infrared spectrum. If that vibration causes a change in the polarization of the molecule (the electron distribution) then it should be observed in the Raman spectrum.
If we look at the data for the van der Waal's radii (Bondi J. Phys Chem 1964, 68, 441):
C 170 pm
N 155 pm
O 150 pm
F 155 pm
Si 210 pm
P 185 pm
S 180 pm
Cl 180 pm
we see that the trend is decreasing radius as one moves from left to right across the periodic table. The...
You say that there are fifteen lanthanides and fifteen actinides, but there are only fourteen. One of the fifteen belongs to the transition metals, but there isn't much agreement on which one. That is, if we look at the fifteen elements La to Lu both La and Lu have a 5d1 electron configuration...
Assuming you mean going from left to right, then the trend is that the radius decreases. The radius decreases because the effective nuclear charge increases.
A quick analysis of the alkali metal hydride crystal structures (and using the Shannon-Prewitt ionic radii for the metals) gives an average 1.3 angstrom (130 pm) radius for H-. Roughly about the same size as an oxide ion.