transition metals

Question 1

D-block elements def
KEY

Answer 1

A d-block element has its highest energy electron in a d-subshell

located between group2-group4

Question 2

anomalies in electron configurations

Answer 2

Cr and Cu both only have 1 electron in the 4s subshell (half full)

making them more stable

Question 3

transition element definition

Answer 3

a transition element is a D-block element that forms an ion with an incomplete d sub-shell

lose 4s electrons first when forming + ions

Question 4

properties of transition elements

Answer 4

variable oxidation states-
3d and 4s energy levels are close in energy so 3d electrons are also easy to lose
ox state must be stated in name of compound

formation of coloured ions-
compounds and salt solutions are coloured

effective catalyst-
e.g. Fe in Haber process

Question 5

Cu2+ reaction with NaOH

include colours

Answer 5

Cu2+ = blue

blue precipitate forms

Ionic equ-
Cu2+(aq) + 2OH-(aq) —> Cu(OH)2(s)

Copper(II) Hydroxide

Question 6

Fe2+ reaction with NaOH

include colours

Answer 6

Fe2+ = pale green

green precipitate forms

Ionic equ-
Fe2+(aq) + 2OH-(aq) —> Fe(OH)2(s)

iron(II) Hydroxide

Question 7

Fe3+ reaction with NaOH

include colours

Answer 7

Fe3+ = yellow

rusty brown precipitate forms

Ionic equ-
Fe3+(aq) + 3OH-(aq) —> Fe(OH)3(s)

iron (III) Hydroxide

Question 8

Mn2+ reaction with NaOH

include colours

Answer 8

Mn2+ = pale pink

light brown precipitate forms

Ionic equ-
Mn2+(aq) + 2OH-(aq) —> Mn(OH)2(s)

manganese(II) Hydroxide

Question 9

Cr3+ reaction with NaOH

include colours

Answer 9

Cr3+ = Violet

Grey-green precipitate forms

Ionic equ-
Cr3+(aq) + 3OH-(aq) —> Cr(OH)3(s)

Chromium(III) Hydroxide

Question 10

Complex ion def
KEY

Answer 10

transition metal ion bonded to one or more ligands by coordinate bonds

Question 11

Ligand def
KEY

Answer 11

a molecular ion that can donate a pair of electrons to the transition metal ion to form a coordinate bond to a metal ion

Question 12

coordinate bond def
KEY

Answer 12

a shared pair electrons ion which one of the bonded atoms provides both the electrons for the shared pair

(its a dative covalent bond)

Question 13

When do transition metals form complex ions
+ example

Answer 13

In solution

[Cu(H20)6]2+

square brackets-group species
overall charge-shown outside square brackets

Question 14

monodentate ligands def
KEY

Answer 14

a molecule or ion that can donate 1 pair of electrons to the transition metal ion to form one coordinate bond

Question 15

examples on monoligands

Answer 15

H20: - neutral
:NH3 - neutral
:Cl- - 1-
:OH- - 1-
thiocyanate (:SCN-) - 1-
:CN- - 1-

Question 16

coordination number def
KEY

Answer 16

is the total number of coordinate bonds formed between a central metal ion and its ligands

Question 17

how many coordinate bonds does a octahedral shaped complex have

Answer 17

6

Question 18

how many coordinate bonds does a tetrahedral(common)/ square planar(rare) shaped complex have

Answer 18

4