transition metals

Question 1

what is a transition metal

Answer 1

element that forms at least one stable ion with a partially filled d subshell

Question 2

key features of transition metals

Answer 2

3CV
-COMPLEX IONS
-COLOURED IONS
-CATALYTIC PROPERTIES
-VARIABLE OXIDATION STATES

Question 3

co ordinate bond

Answer 3

shared pair of electrons which come from the same atom

Question 4

ligand

Answer 4

an ion with a lone pair of electrons which can form a co-ordinate bond with a transition metal ion

Question 5

coordination number

Answer 5

number of coordinate bonds

Question 6

complex ion

Answer 6

central atom or ion surrounded by ligands

Question 7

monodentate

Answer 7

each ligand forms 1 coordinate bond

Question 8

bidentate

Answer 8

each ligand forms 2 coordinate bonds

Question 9

multidentate

Answer 9

each ligand forms more than 2 coordinate bonds

Question 10

octahedral transition metal complex

Answer 10

[Cu(H2O)6]2+

Question 11

tetrahedral transition metal complex

Answer 11

[CoCl4]2-

Question 12

square planar transition metal complex

Answer 12

[Ni(CN)4]2-

Question 13

liners transition metal complex

Answer 13

[Ag(NH3)2]+

Question 14

chelate effect

Answer 14

-occurs when a monodentate ligand is substituted by a bidentate/multidentate ligand
-large increase in entropy which is thermodynamically favourable

Question 15

explain why this reaction is feasible

Answer 15

-^S is positive
-more moles of products so more disorder
-breaking 6 bonds and forming 6 bonds
-^H is approximately zero
-so ^G is less than zero so the reaction is feasible

Question 16

haemoglobin

Answer 16

-O2 forms a coordinate bond to Fe2+ in haemoglobin enabling oxygen to be transported in the blood
-CO is toxic because CO bonds more strongly to Fe2+ in haemoglobin, this prevents oxygen from bonding, causing suffocation

Question 17

stereoisomers

Answer 17

-same structural formula but different spatial arrangement of atoms

Question 18

cisplatin

Answer 18

-cis isomer of [PtCl2(NH3)2]
-anti cancer drug
-prevents DNA from unwinding so cancer cells can’t replicate
-prevents growth and spreading of cancerous cells

Question 19

why are TM coloured

Answer 19

-partially filled d sun shells
-all d orbitals are of equal energy known as ground state
-enables electrons to be excited from one d orbital to another
-when electron moves from the low energy d orbital to high energy, the energy is taken from white light
-colours are passed through sample, give compound colour