Structure 3.1.8 - 3.1.10 - Trends/properties of the period 4 d block elements

Question 1

characteristics of d block elements

Answer 1

(Cu/Cr) special configs that better stabilize the d orbital

d block metals have similar chem/phys properties

relatively small atomic radii, which is why they are useful in making alloys

Question 2

characteristics of transition metals

Answer 2

-incomplete d sublevel
-forms cations w an incomplete d sublevel
- can form complex ions

Question 3

physical properties of transition metals

Answer 3

-high electrical/ thermal conductivity, high mp
-malleable

Question 4

chem properties of transition metals

Answer 4

-act as catalysts (speed up rxn rates)

Question 5

define complex ions

Answer 5

an ion in which a transition metallic cation forms in a coordinate covalent bond w ligands

Question 6

define coordinate covlanet bond

Answer 6

a bond where electrons in the shared pair come from one of the atoms in the bond

Question 7

define ligands

Answer 7

any atom or molecule w at least one lone pair of e-

Question 8

what does each symbol mean in this example of a complex ions

[Fe (H2O) 6] 3+

Answer 8

6=coordination # (how many ligands are attached)
Fe - transition metal cation
H2O=ligand
3+=overall charge on the complex ion

Question 9

How to draw the structure of a complex ion

Answer 9

transition metal in the middle (with its charge)
ligands (with charge) surrounds the metal, with an error pointing toward the transition metal
written inside a [ ], with its overall charge on the outside

Question 10

what is the color of transition metal ions related to

Answer 10

-incomplete d orbitals
-the color we see is related to the color absorbed by some d orbital electrons as a result of a d orbital split

Question 11

explanation to why transition metal ions have colors

Answer 11

-as the ligand approaches to make the coordinate covalent bond, it exerts an electric field via its lone pair of electrons
-this causes a d orbital split (- - - - - to – )
( — )
the d orbital split results in some electrons jumping to a higher energy orbital

Question 12

what factors influence the degree of the split

Answer 12

the charge of the metal cation and the charge density of the ligand.
-greater charge density of ligand=greater split= shorter wavelenght absorbed

these two factors determine the wavelenght absorbed

Question 13

concentration of solution vs wavelenght of absorption

Answer 13

the wavelength of absorption will be the same if the ion + ligands are the same regardless of the concentration of the solution

however, more concentrated solutions will have a greater intensity of absorbance than less concentrated solutions at the same wavelenght