5.3.1 transition metals

Question 1

what do transition metals have that makes them transition metals

Answer 1

incomplete d subshells

Question 2

why is Zn not a transition metal

Answer 2

it can only form a 2+ ion where the d orbitals are complete

Question 3

what are chemical properties of transition metals

Answer 3

forms a complex
forms coloured compounds
variable oxidation state
catalytic activity

Question 4

what are physical properties of transition metals

Answer 4

high density
high melting and boiling point
good conductors

Question 5

what is a complex

Answer 5

a central metal ion surrounded by ligands

Question 6

what is a ligand

Answer 6

an atom, ion or molecule which can donate an electron pair

Question 7

give two properties a cation must have to form a complex ion

Answer 7

high charge density to attract electrons

empty orbitals to accept lone pairs

Question 8

what is a coordinate bond

Answer 8

when a shared pair of electrons in covalent bond come from only one of the bonding atoms

Question 9

what ion forms linear complexes

Answer 9

Ag+

Question 10

what ion forms square planar complexes

Answer 10

pt2+ Ni2+

Question 11

what is a unidentate ligand

Answer 11

ligands which form one coordinate bond to a metal ion

Question 12

what is a bidenate ligand

Answer 12

ligands which form two coordinate bonds to a metal ion

Question 13

what is stereoisomerism

Answer 13

same structural formula but different 3D structure and

Question 14

what is a multidentate ligand

Answer 14

ligands which form more than two coordinate bonds to a metal ion

Question 15

what does haemoglobin contain

Answer 15

four Fe2+ centres which bond to oxygen and carry it around the blood

Question 16

why are cn and co toxic

Answer 16

they are stronger ligands than oxygen so will bond to haemoglobin in preference

Question 17

give the test for carbonate

Answer 17

• add any dilute acid and observe effervescence

* bubble gas through limewater co2 will turn it cloudy

Question 18

give the test for sulphates

Answer 18

•add bacl2 and observe a white precipitate

Question 19

test for halide ions

Answer 19

•add hno3 to remove carbon impurities 
•add agno3 and observe 
cl- white ppt
br-cream ppt
i-yellow ppt

Question 20

give the test for ammonium

Answer 20

• add NaOH(aq) and heat

* NH4(g) would form which turns litmus paper from red to blue

Question 21

give the colour change for positive ions when a hexa aqua complex forms a precipitate

Answer 21

cu2+: blue sol to blue ppt 
mn2+: pale pink sol to brown ppt
fe2+: green sol to green ppt
fe3+: yellow/brown sol to brown ppt
cr3+: green sol to green ppt

Question 22

name the metal ion that reacts with excess oh- and describe what happens

Answer 22

cr hydroxide dissolves and becomes cr(oh)6 green sol