1What is a d-block element?
Elements with their outermost electrons existing in the d-orbital.
2What is a transition metal?
An element that may form stable ions with partially filled d-orbitals
3Which electrons are lost first by a transition metal?
The 4s electrons
4How are transition metals able to form many different stable oxidation states?
The energies of the 4s and 3d orbitals are very similar, so the energy required to achieve higher oxidation states is comparatively low. This may then be compensated for in the additional bonds formed
5What is a ligand?
A small molecule with a lone pair that can coordinately bond to a transition metal to form a complex ion
6What is a complex?
Ligands coordinately bonded to a central transition metal ion
7What colour is Cr iii (as in CrCl 3)
Green
8What colour is the dichromate (Cr₂O₇²⁻) ion?
Orange
9What colour is the chromate (CrO₄²⁻) ion?
Yellow
10What colour is the manganate (MnO₄⁻) ion?
Purple
11What colour is aqueous Co ii ?
Pink
12What colour is aqueous Fe ii ?
Pale green
13What colour is aqueous Fe iii ?
Red-brown
14What colour is Cu ii ?
Blue
15What colour is tetraaminediaquacopper ii ?
Royal blue
16What is a useful industrial application of various transition metals?
As catalysts
17What catalyst is used in the Haber process (the synthesis of ammonia) ?
Iron
18What catalyst is used in the hydrogenation of vegetable oils for the manufacturing of margarine?
Nickel
19What catalyst is used in the contact process (synthesis of sulphuric acid) ?
Vanadium (V) oxide
20What catalyst is used in the catalytic decomposition of hydrogen peroxide?
Manganese (iv) oxide
21Which d-block metals exhibit amphoteric behaviour?
Chromium and zinc
22What happens when dilute NaOH is added to an aqueous solution of Cr 3+
Triaquatrihydroxychromium is formed as a gelatinous green precipitate
23What happens when concentrated NaOH is added to an aqueous solution of Cr 3+
Triaquatrihydroxychromium is formed, which further reacts to form Diaquatetrahydroxychromium-, which redissolves, giving a green solution
24Why do transition metals exhibit colour?
D-orbital splitting
25What is an important use of transition metals in living systems?
The production of hemoglobin to transport oxygen throughout animals
26What reagent is required to form hexaaminediaquacopper ii from a solution of aqueous copper ii?
Dilute ammonia
27What is an example of a linear complex molecule?
[AgCl₂]⁻ (dichloroargentate i)
28What is the colour of the aqueous tetrachlorocuprate ii complex?
Yellow-green
29What are the 3 stages of heterogenous catalysis?
Adsorption, reaction, desorption
30What would you see upon addition of NaOH to an aqueous solution of Zinc?
An white precipitate will form initially (Zn(OH)₂) will form, which redissolves upon addition of excess NaOH (Forming [Zn(OH)₄]²⁻
31Why do transition metal complexes exhibit colour?
The presence of ligands causes a splitting in energy level of the d-orbitals, and vacancies in the newly formed upper energy state facilitate the promotion of electrons from the lower state to the higher state through the absorption of specific frequencies of photons. This results in colour.