Dative Covalent Bonding

Question 1

What is a dative covalent bond?

Answer 1

One atom supplies both shared electrons to covalent bond

Question 2

What represents a dative covalent bond?

Answer 2

A→B

Question 3

What does the arrow direction represent in a dative covalent bond?

Answer 3

Direction electron pair has been donated

Question 4

Once bonded, what is the dative covalent bond equivalent to?

Answer 4

All other covalent bonds

Question 5

What happens when an acid is added to water?

Answer 5

Oxonium ions (H₃O⁺) form

Question 6

What are oxonium ions often simplified to?

Answer 6

H⁺(aq)

Question 7

Why might the outer rule not always be reached?

Answer 7

• May not be enough electrons to reach an octet
• More than four electrons may pair up in bonding (known as expansion of octet)

Question 8

When is the octet expanded?

Answer 8

• Elements in groups 15–17 from period 3
• Moving down periodic table, more outer-shell electrons are able to take part in bonding
• In resulting molecules, one bonding atom may end up with more than eight electrons in its outer shell

Question 9

How many covalent bonds can group 15 atoms form?

Answer 9

3 or 5

Question 10

How many covalent bonds can group 16 atoms form

Answer 10

2, 4 or 6

Question 11

How many covalent bonds can group 17 atoms form

Answer 11

1, 3, 5 or 7

Question 12

What is a better rule than the octet rule?

Answer 12

• Unpaired electrons pair up
• Maximum electron numbers that can pair up is equal to electron numbers in outer shell