TRANSITION METALS

Question 1

How do characteristics arise in transition metals

Answer 1

due to the incomplete d sublime within atoms and elements.

Question 2

what is a ligand

Answer 2

A ligand is a molecule or ion that forms a coordinate bond with transition metal by donating a pair of electrons

Question 3

what is a complex

Answer 3

central metal ion surrounded by ligands

Question 4

what is the coordination number

Answer 4

number of coordinates bonds to the central metal atom or ion

Question 5

what is a unidenteligand

Answer 5

form one coordinate bond per ligand

Question 6

what is a bidente ligand

Answer 6

two atoms with lone pairs and can form two coordinate bonds per ligand

Question 7

how is stability determined

Answer 7

substitution of mondenete ligand with a bidente or multi dente will lead to a more stable complex

Question 8

how can a reaction be feasible

Answer 8

if Gibbs free energy is negative

Question 9

why can transition metals become coloured ions

Answer 9

they are degenerate- contain the same energy- the d orbital will split into two energy levels in octahedral and tetrahedral complex, the colour will arise from electronic transitions from the ground state to the excited state between different d orbitals. A proton of visible light will be absorbed to promote d electrons to higher energy levels so that the light that is not absorbed is transmitted to give a colour.

Question 10

how does colour change arise

Answer 10

change in oxidation state, coordination number and ligands, they alter energy split between the d orbitals changing the coordination number and altering the energy split between the d orbitals changing the frequency of light absorbed. The particular wavelengths of light will be absorbed so remains wavelengths are the colour perceived.

Question 11

what are the physical properties of TM

Answer 11

dense metals, high melting and boiling point, hard and durable, high tensile strength, high electrical conductivity and malleable

Question 12

variable oxidation state

Answer 12

all tm contain more than one oxidation state, the highest oxidation state is when they readily accept electron which make them powerful oxidising agents

Question 13

catalytic activity

Answer 13

they are made catalyst by providing surface for reaction to take place and bind to reactants to form intermediates

Question 14

heterogenous catalyst

Answer 14

spread onto a support medium to maximise their surface are and minimise costs

Question 15

CONS of heterogenous catalyst

Answer 15

can become poisoned by impurities that block active sites and consequently have reduced efficiency these can be expensive to replace.

Question 16

chemical properties of transition metals

Answer 16

coloured ions, complexes, variable oxidation state, catalytic activity

Question 17

how are tm able to have variable oxidation states

Answer 17

they are able to donate and receive electrons and can oxidise and reduce because they have many electrons of similar energy in the valence- shell orbital

Question 18

why is the acidity of [M(H2O)6]3+ is greater than [M(H2O)6]2+

Answer 18

metal ion swill become hydrated in water with ligands around central ions, major aqua ions will form coloured precipitate that they can identify metal ions with. their means when the ions is acidic, metal ions for 2+ ions which will be weaker compared to 3+. therefore the 3+ dissociate more and have greater attraction power to the OH ion, because they are stronger. with NaOH the solution of these metal will react as an acid with sodium hydroxide in a neutralisation reaction to form salt and water.

Question 19

what does amphoteric mean

Answer 19

act as both acid and base

Question 20

test tube reaction of OH ion

Answer 20

neutralisation reaction to form salt and water these reaction hydrolyse the metal ions to form coloured ions

Question 21

test tube reaction of NH3 ion

Answer 21

form salt and ammonium ions, when ammonium is added in excess to these precipitate the copper salt undergoes ligand substitution to form deep blue solution

Question 22

test tube reaction of 2+ ion of co32-

Answer 22

acids forming insoluble carbonates in water

Question 23

test tube reaction of 3+ ion of CO32-

Answer 23

stronger acid meaning they react with sodium carbonate to form salt, water and carbon dioxide

Question 24

test tube reaction of cl ion

Answer 24

ligand substitution to form tetrahedral ions with 4 cl- ligands, this occurs when they react with concentrated hydrochloric acid