10.18 compare the lewis structures of ch₄ and h₂o. why do these molecules have similar bond angles but…
10.18 compare the lewis structures of ch₄ and h₂o. why do these molecules have similar bond angles but different molecular shapes?
Answer
Brief Explanations:
The Lewis structure of CH₄ has a central carbon atom with 4 bonding pairs and no lone - pairs, giving it a tetrahedral electron - pair geometry and molecular shape with bond angles of approximately 109.5°. The Lewis structure of H₂O has a central oxygen atom with 2 bonding pairs and 2 lone - pairs. The electron - pair geometry is tetrahedral, similar to CH₄, which results in similar bond angles (slightly less than 109.5° due to lone - pair repulsion). However, the presence of the two lone - pairs in H₂O causes the molecular shape to be bent, while CH₄ is tetrahedral.
Answer:
The electron - pair geometries of CH₄ and H₂O are similar (tetrahedral), leading to similar bond angles. But the presence of lone - pairs in H₂O (2 lone - pairs on O) and no lone - pairs in CH₄ (4 bonding pairs on C) results in different molecular shapes (bent for H₂O and tetrahedral for CH₄).