Most training programs for LPNs last about 2 years and are offered by vocational or technical schools, or community or junior colleges.

Which of the following is a minimum requirement for environmental scientists and specialists?

What are at least 3 potential problems with maps, or things we should watch out for before we rely on a map for information?

The rate constants (at 45 ºC) for the anation of [Co(NH3)5H2O]3+ with three anions are shown below (Please write your answer on a paper and upload the image fine in the Assignments).  (a) Are these data consistent with a dissociative or associative mechanism?  Briefly explain your answer.  (b) Write the rate equation that is consistent with your choice in (a). (c) Write an equation (reaction) for the rate-determining step of these reactions.    

The spinels have a general formula AIIB2IIIO4.  The oxide anions form a ccp (fcc) lattice and the cations occupy the tetrahedral or octahedral holes.  For NiFe2O4, please answer to the following questions (Please write your answer on a paper and upload the image file in the Assignments) : (a) Determine the CFSEs of Ni2+ occupying the tetraheral and octahedral holes in terms of Δo.  You must draw the electron configurations in the energy level diagrams (Note: The oxides are weak-field (high-spin) ligands and Δt ~ (1/2) Δo).      (b) Determine the CFSEs of Fe3+ occupying the tetraheral and octahedral holes in terms of Δo.  You must draw the electron configurations in the energy level diagrams (Note: The oxides are weak-field (high-spin) ligands and Δt ~ (1/2) Δo).      (c) Which cation (Ni2+, Fe3+) prefers the octahedral holes more strongly?  Briefly explain your answer. (d) Would you expect NiFe2O4 to form a normal or inverse spinel?  Briefly explain your answer.

The electron affinities of Al, Si, and P are -43, -134, and -72 kJ/mol, respectively.  Please choose all correct statements regarding the relative values of these electron affinities (there may be more than one answer).

Rhodium (Rh) crystallizes in a face-centered cubic arrangement.  Calculate the total volume of Rh atoms present in a face-centered cubic unit cell (r is the atomic radius of Rh).  

An ionic compound forms a cubic-type lattice where A ions occupy the corners of the cube and B ions occupy the centers of faces of the cube.  What is the molecular formula of the compound?   

The radii of Mg2+ and S2- are 0.86 and 1.70 Å, respectively.  Therefore, the radius ratio of MgS is   _______ , which indicate that the maximum coordination number for the magnesium cation should be _______ .  If MgS assumes a rock-salt structure (NaCl), the S2- will form a _______ lattice and Mg2+ will occupy  _______ holes.

Answer to the following questions for [Ru(NH3)6]3+ (Please write your answers on a paper and upload the image file in the Assignments): (a) Determine the CFSE for the high-spin case (Please include the electron configuration). (b) Determine the CFSE for the low-spin case (Please include the electron configuration).  (c) What is the condition when the low-spin state is favored (the condition must be supported by the results in (a) and (b))?  (d) Please predict which spin state is favored, and explain your choice based on all factors (size, charge, ligand, …) affecting the magnitude of the crystal field splitting energy of this compound.