Photo AI
Define electronegativity - Leaving Cert Chemistry - Question b - 2003
Question b
Define electronegativity. Describe using dot and cross diagrams the bonding in the water molecule. What is the shape of the water molecule? Which of the following ... show full transcript
Worked Solution & Example Answer:Define electronegativity - Leaving Cert Chemistry - Question b - 2003
Step 1
Step 2
Describe using dot and cross diagrams the bonding in the water molecule.
Answer
The water molecule, H₂O, consists of two hydrogen atoms and one oxygen atom. In dot and cross diagrams, the oxygen atom has six electrons in its outer shell, while each hydrogen atom has one electron.
The bonding can be illustrated as follows:
. .
O
/ \
H H
In this diagram, the dots represent the electrons from the oxygen atom, and the crosses represent the electrons from the hydrogen atoms, indicating the sharing of electrons.
Step 3
Step 4
Which of the following angles, 104°, 107°, 109°, 120° or 180° would you expect to be closest to the bond angle in the water molecule? Explain your answer.
Answer
I would expect the bond angle in the water molecule to be closest to 104°. This is due to greater repulsion by lone pairs of electrons. The two lone pairs on the oxygen exert repulsion, pushing the bonds between the hydrogen atoms closer together, which reduces the bond angle from the ideal tetrahedral angle (109.5°) to approximately 104°.