DM - Transition Elements

Question 1

what is a reactions rate?

Answer 1

the change in conc. per second

Question 2

what are the characteristics of the d block elements within the periodic table?

Answer 2

the elements with the highest energy electrons in a d orbital

Question 3

what are the properties of the d black elements?

Answer 3

high melting point
high boiling point
hard
good conductors of electricity and heat

Question 4

in what way do Cr and Cu not fit the same pattern of filling their orbitals?

Answer 4

instead of 4s filling before 3d:
Cr = half of 3d filled then one in 4s
Cu = full 3d and one in 4s
because it is more stable

Question 5

what are transition ions?

Answer 5

d block elements which FORM IONS with a partially filled d sub shell

Question 6

which 2 d block elements cannot be transition metals?

Answer 6

scandium and zinc

Question 7

why can’t scandium and zinc be transition metals?

Answer 7

because Sc3+ has an empty d sub shell
and Zn2+ has a full d sub shell

Question 8

what are the properties of transition metals?

Answer 8

VARIABLE OXIDATION STATES

Question 9

how do transition metals form coloured compounds?

Answer 9

colour is associated with presence of a partially filled d orbitals in ion metals

Question 10

what must an atom have to be able to absorb light?

Answer 10

light is absorbed by an atom only if energy of the light matches the energy gap between 2 energy states in the electron

Question 11

what happens when d block elements absorb light?

Answer 11

electron is excited and promoted to a higher energy level from its ground state
the difference between the 2 levels /\E is now proportional to the light absorbed
the visible light not absorbed is what is seen = the complimentary colour

Question 12

what does the colour of transition metals depend on?

Answer 12

number of d electrons present in transition metal ion
arrangement of ligands around the ions as this effects splitting of d shell
nature of ligands as they have different effects on the relative energies

Question 13

complex ion shape:
tetrahedral
octahedral
square planar

Answer 13

tetrahedral = 109.5
octahedral = 90
square planar = 90
(add arrows and lone pairs to diagrams)

Question 14

what is a ligand?

Answer 14

a molecule or ion with a lone pair that is able to from a dative/coordinate bond with the central metal ion by donating its lone pair of e-

Question 15

what is a monodentate ligand?

Answer 15

ligand each forms one coordinate bond

Question 16

what is a bidentate ligand?

Answer 16

ligand each forms 2 coordinate bonds

Question 17

what is a polydentate ligand?

Answer 17

bond through more then one atom/ion

Question 18

why can transition metals act as catalysts?

Answer 18

due to varying oxidation state

Question 19

what type of catalysts can transition metals act as?

Answer 19

heterogeneous = diff states to reactants (chemisorption - 4 stages)
homogeneous = same state as reactants

Question 20

how do TM act as catalysts?

Answer 20

by donating their lone pair of electrons