1.4.4 Dative Covalent Bonding

Question 1

In simple covalent bonds, the two atoms involved

Answer 1

share electrons

Question 2

Some molecules have a

Answer 2

lone pair of electrons

Question 3

Some molecules have a lone pair of electrons that can be donated to form a bond with

Answer 3

an electron-deficient atom

Question 4

An electron-deficient atom is an atom that has

Answer 4

an unfilled outer orbital

Question 5

So both electrons are from

Answer 5

the same atom

Question 6

This type of bonding is called

Answer 6

dative covalent bonding or coordinate bonding

Question 7

An example with a dative bond is in an ammonium ion
- The nitrogen atom in ammonia has

Answer 7

a lone pair of electrons which it can donate to the hydrogen ion to form a dative covalent bond

Question 7

An example with a dative bond is in an ammonium ion
- The hydrogen ion, H+ is

Answer 7

electron-deficient and has space for two electrons in its shell

Question 8

Ammonia (NH3) can donate a lone pair to an electron-deficient proton (H+) to form a charged ammonium ion (NH4+) diagram

Answer 8

Question 9

Aluminium chloride is also formed using

Answer 9

dative covalent bonding

Question 10

At high temperatures aluminium chloride can exist as

Answer 10

a monomer (AlCl3)

Question 11

The aluminium chloride molecule is electron-deficient and needs

Answer 11

two electrons to complete the aluminium atom’s outer shell

Question 12

At lower temperatures the two molecules of AlCl3 join together to form

Answer 12

a dimer (Al2Cl6)

Question 13

The aluminium chloride molecules combine because

Answer 13

lone pairs of electrons on two of the chlorine atoms form two coordinate bonds with the aluminium atoms

Question 14

Aluminium chloride is also formed with a dative covalent bond in which two of the chlorine atoms donate their lone pairs to each of the aluminium atoms to form a dimer diagram

Answer 14