inorganic - transition metals

Question 1

the 10 metals in the 3d block

Answer 1

• titanium (Ti)
• vanadium (V)
• chromium (Cr)
• manganese (Mn)
• iron (Fe)
• cobalt (Co)
• nickel (Ni)
• copper (Cu)

Question 2

transition metal characteristics of Ti-Cu arise from…

Answer 2

having an incomplete d sub-shell in atoms or ions

Question 3

electron configuration of d block elements in the case of Ti, V, Mn, Fe, Co, and Ni

Answer 3

• two outer 4s electrons
• as you go across the period, the electrons are added to the inner 3d sub-shell
  electron configurations:
• Ti: [Ar] 3d2 4s2
• V: [Ar] 3d3 4s2
• Mn: [Ar] 3d5 4s2
• Fe: [Ar] 3d6 4s2
• Co: [Ar] 3d7 4s2
• Ni: [Ar] 3d8 4s2

Question 4

electron configuration of d block elements in the case of Cu and Cr

Answer 4

• copper and chromium do not follow the usual pattern of electron arrangement
• copper has a full d sub-shell, but only one outer 4s electron
  Cu: [Ar] 3d10 4s1
• chromium has a half full d sub-shell, but only one outer 4s electron
  Cr: [Ar] 3d5 4s1

Question 5

definition of a transition element

Answer 5

an element which forms a stable ion with an incomplete/part full d-shell of electrons
- they lose electrons to form positive ions, electrons of s-shell are lost first

Question 6

why Zn2+ and Sc3+ are not considered to be transition elements

Answer 6

• scandium only forms Sc3+ in all of its compounds
• Sc3+ has an empty d-shell (3d0)
• zinc only forms Zn2+ in all of its compounds
• Zn2+ has a full d-shell (3d10)

Question 7

physical properties of transition metals

Answer 7

1) good conductors of heat and electricity
2) high melting and boiling points
3) shiny
4) hard and strong

Question 8

chemical properties of transition metals

Answer 8

1) variable oxidation states
e.g. Fe(ii) and Fe(iii)
they can therefore take place in many redox reactions
2) can form coloured ions
3) catalysis: catalysts affect the rate of reactions without being chemically used up or altered
- many transition metals and their compounds show catalytic activity
e.g. iron in haber process, vanadium in contact process, manganese oxide in the decomposition of hydrogen peroxide
4) complex formation
- transition metals form complex ions
- complex ions are formed when a transition metal ion is surrounded by ions or other molecules called ligands
- using co-ordinative bonding
e.g. [Cu(H2O)6]2+