Transition Metals

Question 1

An Orbital

Answer 1

A region of an element in which you can find electrons

Question 2

Order of the Transition Metals

Answer 2

Scandium
Titanium
Vanadium
Chromium
Manganese
Iron
Cobalt
Nickel
Copper
Zinc

Question 3

A transition element is an element which..?

Answer 3

Possesses a filled or partially filled valence d orbitals in one or more of its oxidation states.

Question 4

Are all d-block metals transition metals.?

Answer 4

Transition Metals are part of d-block of the periodic table of elements, but not all d-block metals may be considered transition metals (e.g Scandium & Zinc)

Question 5

To be a d-block element, a transition metal must..?

Answer 5

To be a d-block element, a transition metal must have an incompletely filled d-orbital

Question 6

Reasons for the catalytic properties of d-block elements

Answer 6

1. They have unoccupied d-orbitals
2. They are capable of displaying a range of valencies
3. They have a proclivity for forming complicated chemicals

Question 7

Why are transition metals excellent catalysts..?

Answer 7

Transition metals are excellent catalysts due to the availability of 3d and 4s electrons and their ability to change oxidation state.

Question 8

Factors For The Catalytic Properties Of Transition Metals

Answer 8

1. Variable Oxidation State
2. Large surface area

Question 9

Types Of Catalysts

Answer 9

1. Homogeneous
2. Heterogeneous (Solid)
3. Heterogenised Homogeneous
4. Biocatalysts

Question 10

Why do Nickel & Platinum make excellent catalysts..?

Answer 10

Because they adsorb strongly enough to hold and activate the reactants while allowing the products to escape

Question 11

Catalyst

Answer 11

A component that changes the rate of a reaction by guiding it down a different path that requires less energy to activate

Question 12

DTPA⁵-

Answer 12

Diethylene triamine penta acetic acid

A complexing agent used for gadolinium

Question 13

A ligand which served as a complexing agent used for gadolinium

Answer 13

DTPA⁵-

Question 14

Applications Of Complexes

Answer 14

In detergents
As a commercial water softener
In M.R.I[Magnetic Resonance Imaging] in Medicine

Question 15

In photographic processing, excess AgBr is dissolved using what..?

Answer 15

A concentrated solution of sodium Thiosulfate(Used in generating black and white film)

Question 16

Complex Ions

Answer 16

The electrically charged complexes with a metal ion in the center which is surrounded and linked by a number of neutral molecules or negative ions

Question 17

Ligands

Answer 17

The neutral molecules or negative ions

Question 18

Because of a Lewis acid-base interaction, a complex ion forms..?

Answer 18

A metal ion and a ligand

Question 19

The neutral molecules or negative ions

Answer 19

Ligand

Question 20

Why does a complex ion form metal ion and a ligand..?

Answer 20

Because of a Lewis acid-base interaction

Question 21

Oxidation State Trend In Transition Metals

Answer 21

From left to right, the number of common oxidation states increases at first to a maximum towards the middle of the table then decreases.

Question 22

Ionization Energies Trends Of Transition Metals

Answer 22

The build up of electrons in the immediately underlying d-sub shells that efficiently shields the 4s electrons from the nucleus and minimizing the increase in effective nuclear charge Zeff from element to element causes a small change in values of the 1st & 2nd ionization energies to be observed from Scandium to Zinc

Question 23

Electronic Configuration Trends Of Transition Metals

Hint: 5 points

Answer 23

• It is basically the same for the first row transition elements.
• There is a gradual filling of the 3d orbitals across the series starting from Scandium
• At Chromium & Copper, the population of 3d orbitals increase by acquisition of an electron from the 4s shell.
• In Chromium: both 3d & 4s orbitals are occupied but neither is filled: so, both energies of the orbitals are relatively close for atoms in this row.
• In Copper: the 3d is full but only 1 electron is in the 4s shells; therefore, the 3d orbital energy is lower than the 4s orbital.

Question 24

Melting & Boiling Points Trends Of Transition Metals

Hint: 2 points

Answer 24

• Due to the strong metallic bonding in transition metals, the melting point and molar enthalpies of fusion are high(in comparison to other main group elements)
• The strong metallic bond is due to delocalization of electrons, facilitated by the availability of both d and s electrons.

Question 25

Densities & Metallic Radius Trends Of Transition Metals

Answer 25

•Transition Elements are much denser than the s-block elements •There is a gradual increase in density from Scandium to Copper(due to the small & irregular decrease in metallic radii coupled with the relative increase in atomic mass)

Question 26

Physical Properties Of Transition Metals Hint: 8 points

Answer 26

• Have large charge/radius ratio • Are hard & have high densities • Have high melting and boiling points • Form compounds which are often paramagnetic • Show variable oxidation states • Form coloured ions and compounds • Form compounds with profound catalytic activity • Form stable complexes

Question 27

Properties And Trends In Transition Metals Hint: 2 points

Answer 27

• Electrons in the outer shells of the atoms of these elements have little shielding effects resulting in an increase in effective nuclear charge due to the addition of protons in the nucleus. • The first 10 transition metals possess similarities in properties(physical and chemical) because of their relatively small difference in effective nuclear charge over the series.