Struture And Bonding

Question 1

What is a pure covalent bond?

Answer 1

• Pure covalent bonds are formed between two atoms with the same electronegativity value.
• The atoms have an equal attraction for electrons in the covalent bond.

Question 2

Which Van der Waals’ forces hold the pure covalent bonds together?

Answer 2

•Pure covalent bonds are held together by LDF (London Dispersion Forces) which are the weakest forces of attraction and this is caused by the uneven distribution of electrons.

Question 3

What is a Polar covalent bond?

Answer 3

• Polar covalent bonding are formed when two atoms with different Electronegativity values form a covalent bond.
• The atom with higher Electronegativity value is S- and the atom with lower value is S+.

Question 4

Which Van der Waals’ forces hold the polar covalent bonds together?

Answer 4

• Polar molecules are held together by Pdp-Pdp interactions or hydrogen bond.
• Pdp-Pdp interactions occur between polar molecules where the molecule had a perm any dipole, for example between ICI molecule
• Hydrogen bonding occurs between polar molecules where an H atom is directly bonded to an N, O or F atom.
• Hydrogen bonding is caused by a large difference is Electronegativity.

Question 5

What is an ionic bond?

Answer 5

• Ionic bond is an electrostatic attraction between positive and negative ions.
• The most common ionic compounds are formed between metals and non-metals.
• A electronegativity difference of 2.0 and above generally indicates that bonding is more ionic than covalent and is usually referred to as ionic.
• The metal has a low electronegativity value and the non-metal has a much higher electronegativity value.

Question 6

What are the 3 Van der Waals’ forces?

Answer 6

• London dispersion Forces (LDF) - the weakest attractive force.
• Permanent dipole- permanent dipole interactions - stronger than LDF.
• Hydrogen bonding - the strongest of the 3 intermolecular attractions.