transition metals

Question 1

what is a transition metal?

Answer 1

A metal that can form one or more stable ions with a partially filled d sub-shell

Question 2

why aren’t scandium and zinc transition metals

Answer 2

as their stable ions don’t have any incomplete d sub shells

Question 3

what is a complex

Answer 3

a metal ion surrounded by co-ordinately bonded ligands

Question 4

what is a ligand

Answer 4

an atom ion or molecule that donates a pair of electrons to a central metal ion

Question 5

Why are transition metals good catalysts

Answer 5

Because they can change their oxidation states by gaining or losing electrons within their d orbital this means they can transfer electrons to speed up reactions

Question 6

what are the three things that change the colour of a transition metal ion

Answer 6

changes in oxidation state
changes in co-ordination number
changes in ligand

Question 7

what is an autocatalyst

Answer 7

a product of a reaction that is a catalyst for the reaction itself

Question 8

name a transition metal complex that occurs in the body

Answer 8

hameoglobin

Question 9

name a transition metal complex that is an anti cancer drug

Answer 9

cis-platin

Question 10

suggest a feature of silver chemistry which is characteristics of the transition elements

Answer 10

complexes

Question 11

suggest a feature of silver chemistry which is not characteristic of the transition elements

Answer 11

colourless compounds

Question 12

give the full electron configuration of a copper atom

Answer 12

ls2 2s2 2p6 3s2 3p6 3d10 4s1

Question 13

What is meant by the term bidentate as applied to a ligand?

Answer 13

it has 2 lone pairs bond to the central metal ion

Question 14

what is co-ordination number

Answer 14

the number of co-ordinate bonds

Question 15

give on example of a bidentate ligand

Answer 15

C2O42-

Question 16

what is a monodentate ligand

Answer 16

a ligand that can only form one co-ordinate bond

Question 17

what is ligand substituion

Answer 17

when one ligand can be swapped for another ligand

almost always causes colour change

Question 18

what happens to shape and co-ordination number if the ligands involved in ligand substiution are the same size

Answer 18

the shape and co-ordination number stays the same

Question 19

what happens to shape and co-ordination of complex if the ligands in substituiton reaction are different sizes

Answer 19

co-ordination number changes as well shape

Question 20

what is the colour of the precipitate formed when [Fe(H2O)6]3+ reacts with Na2CO3

Answer 20

a brown precipitate forms

along side bubbles

Question 21

what is the colour of the solution formed when [Fe(H2O)6]3+ reacts with OH- or NH3

Answer 21

brown precipitate forms

Question 22

what happens to the energy levels of a transition metal ion when a ligand binds

Answer 22

when ligands bond to the ions
some orbitals are given more energy than others.
this split the 3d orbitals into energy levels
electrons tend to occupy lower energy orbitals
to jump up to the higher energy orbitals they need energy equal to the energy gap they get the energy from visible light

Question 23

what decides the colour of transition metal compounds

Answer 23

when visible light hits a transition metal ion
some frequencies are absorbed
as electrons jump up to higher orbitals
the frequencies absorbed depend on the size of the energy gap
the rest of the frequencies are reflected
these combine to make the complement of the colour of the absorbed frequencies

Question 24

what is catalyst poisoning

Answer 24

impurities bind to the active site of the catalyst

reducing the surface area that the reactants can bind to

Question 25

how can catalyst poisoning be prevented

Answer 25

by purifying the reactants

Question 26

where does the reaction occur with a heterogenous catalyst

Answer 26

on the surface of the catalyst

Question 27

how does a homogenous catalyst work?

Answer 27

they make an intermediate species
the reactants combine with the catalyst to form the intermediate species
which then reacts to form the products and reform the catalyst

Question 28

what is chelation

Answer 28

the process by which a multidentate ligand replaces a monodentate ligand in forming co-ordinate bonds to a transition metal ion