A2.7 Transition Elements

Question 1

Transition elements

Answer 1

A d block element with at least one stable ion with a partially filled d subshell

Question 2

Exceptions in d block

Answer 2

Sc and Zn - Sc 3+ - 3d0
Zn 2+ - 3d10

Question 3

Removing e- from transition elements

Answer 3

Take from 4s first

Cr and Cu - take one from 4s then the rest from 3d - more stable
4s13d5 and 4s13d10

Question 4

Features of a transition element

Answer 4

Existence of more than one oxidation state with a partially filled d sub shell

They form coloured ions

They demonstrate catalytic behaviour

Question 5

Ligands

Answer 5

A molecule or ions that donates a pair of electrons to a transition element to form a coordinate bond

Question 6

Monodentate ligands

Answer 6

OH-
H2O
NH3
Cl-
CN-

Question 7

Bidentate ligands

Answer 7

A molecule or molecular ion which donates two lone pairs of electrons per molecule to a transition element to form two coordinate bonds

Question 8

Complex ions

Answer 8

A transition element ion surrounded by ligands in coordinate bonds

Question 9

Coordinate numbers

Answer 9

Number of bonds to a transition element ion from ligands

Question 10

Structure of complex ion

Answer 10

Straight line
Two dashed lines
Two wedges
Straight line

Question 11

Stereoisomerism in complex ions - cis trans

Answer 11

Cis - same group 90 degrees
Trans - same group 180 degrees

Question 12

Optical isomerism in complex ions

Answer 12

Non superimposable

Question 13

Haemoglobin

Answer 13

Transports oxygen round body
Coordinate bond to O2 is very weak
O2 is replaced by CO2
Coz poisoning happens when CO binds instead of O2
CO creates stronger bond than O2 and prevents O2 transportation
Leads to drowsiness and potential death