2A1 Transition metals

Question 1

Define transition element?

Answer 1

Element with an incomplete d-subshell in its atoms or ions

Question 2

How and why is chromium unusual?

Answer 2

It prefers to have a half-full s and d-subshell than to fill in normal sequence

This causes less repulsion as all six outer electrons occupy orbital singly

Question 3

How and why is copper unusual?

Answer 3

It prefers to have a full d-subshell than a full s-subshell

So 1e- in s-subshell is promoted

Question 4

What cation is not transitional with specific charge and why?

Answer 4

Zn, Sc3+, Cu+, Zn2+

Question 5

What is characteristic or properties of transition metals?

Answer 5

Form complex ions

Form coloured ions

Have variable oxidation states

Show catalystic activity

Question 6

Define complex?

Answer 6

Contains a centran metal atom or ion surrounded by ligands which are bonded co-ordinately

Question 7

Define ligands?

Answer 7

Molecules or ions with and available lone pair of electrons

Question 8

Give common ligands and whether neutral or charged?

Answer 8

H2O and NH3 which are neutral

Cl-, OH-, CN-, en, ethanedioate ion which are negative

Question 9

How does ethanedioate ion look?

Answer 9

COO:-
|
COO:-

Question 10

How does en(1,2-diaminoethane) look?

Answer 10

: :
H2NCH2CH2NH2

Question 11

How many charges does EDTA and how many lone pair e-?

Answer 11

4-
Six lone pair e-

Question 12

Give 2 examples of multidentate ligand?

Answer 12

EDTA and HAEM

Question 13

Structure of haemoglobin?

Answer 13

HAEM group has 4 coordination point with N atom, and plane by porphyrin, and 5th position by N from protein called globin and final position by O2 when carrying it

Question 14

State common shape of complex ion and angle?

Answer 14

Octahedral, 90 degrees

Tetrahedral, 109.5 degress

Square planar, 90 degrees

Question 15

What is shape of complex ion often found in Ag+ and Cu+ and angle?

Answer 15

Non-linear, 104.5 degrees

Question 16

Which and why an ion is colourless?

Answer 16

Cu+, Ag+, Zn2+, and Sc3+

Because they have complete d-subshell

Question 17

Fe, green to brown

Answer 17

[Fe(H₂O)₆]²⁺ to [Fe(H₂O)₆]³⁺

Question 18

Cu, blue to green

Answer 18

[Cu(H₂O)₆]²⁺ + 4Cl^- to [CuCl₄]^2- + 6H₂O

Question 19

Cu, blue to deep blue

Answer 19

[Cu(H₂O)₆]²⁺ + 4NH₃ to [Cu(NH₃)₄(H₄O)]²⁺ + 4H₂O

Question 20

Define catalyst?

Answer 20

Speeds up the rate of a reaction but remains chemically unchanged at the end

Question 21

How does catalyst work?

Answer 21

Provides an alternative route for a reaction with a lower activation energy

Question 22

Harber process?

Answer 22

N₂(g) + 3H₂(g) → 2NH₃(g)

450 degrees celcius
100 kPa
Solid Fe catalyst

Question 23

Cr, orange

Answer 23

Cr₂O₇^-2

Question 24

Cr, green

Answer 24

Cr³⁺(aq)

Question 25

Cr, blue

Answer 25

Cr²⁺(aq)

Question 26

Mn, purple

Answer 26

MnO₄^-

Question 27

Mn, pale pink or colourless

Answer 27

[Mn(H₂O)₆]²⁺

Question 28

Contact process?

Answer 28

2SO₂(g) + O₂(g) → 2SO₃(g)

400 degrees Celsius

100-200 kPa

V₂O₅

Question 29

Hydration?

Answer 29

CH₂=CH₂(g) + H₂O(g) → CH₃CH₂OH(g)

300 degrees celcius

7 MPa

H₃PO₄