1. PH₃ (Phosphine)
* Shape: Trigonal pyramidal
* Reasoning: Phosphorus has 5 valence electrons, and forms 3 single bonds with hydrogen atoms and has one lone pair. This leads to a tetrahedral electron geometry but a trigonal pyramidal molecular shape due to the lone pair.
2. CH₄ (Methane)
* Shape: Tetrahedral
* Reasoning: Carbon has 4 valence electrons and forms 4 single bonds with hydrogen atoms. This leads to a perfectly tetrahedral structure.
3. HClO (Hypochlorous acid)
* Shape: Bent
* Reasoning: Chlorine has 7 valence electrons, oxygen has 6, and hydrogen has 1. Chlorine forms a single bond with oxygen, and oxygen forms a single bond with hydrogen. Chlorine has 3 lone pairs and oxygen has 2 lone pairs. This leads to a tetrahedral electron geometry around oxygen but a bent molecular shape due to the lone pairs.
4. N₂ (Nitrogen gas)
* Shape: Linear
* Reasoning: Nitrogen has 5 valence electrons, and each nitrogen atom forms a triple bond with the other nitrogen atom. This leads to a linear structure.
5. CH₃NH₂ (Methylamine)
* Shape: Trigonal pyramidal (around the nitrogen atom)
* Reasoning: Carbon has 4 valence electrons and forms 4 single bonds (3 with hydrogen and 1 with nitrogen). Nitrogen has 5 valence electrons, and forms 3 single bonds (1 with carbon and 2 with hydrogen) and has 1 lone pair. This leads to a tetrahedral electron geometry around nitrogen but a trigonal pyramidal molecular shape due to the lone pair.
6. H₂CO (Formaldehyde)
* Shape: Trigonal planar
* Reasoning: Carbon has 4 valence electrons, forms two double bonds (one with oxygen and one with a carbon atom), and two single bonds with hydrogen atoms. This leads to a trigonal planar geometry.
7. C₂H₂ (Acetylene)
* Shape: Linear
* Reasoning: Carbon has 4 valence electrons, and each carbon atom forms a triple bond with the other carbon atom and a single bond with a hydrogen atom. This leads to a linear structure.
8. CH₃Cl (Chloromethane)
* Shape: Tetrahedral
* Reasoning: Carbon has 4 valence electrons and forms 4 single bonds (3 with hydrogen and 1 with chlorine). This leads to a tetrahedral structure.
9. HCOOH (Formic acid)
* Shape: Planar (around the carbonyl carbon) and bent (around the oxygen atom)
* Reasoning: Carbon has 4 valence electrons and forms a double bond with oxygen, a single bond with another oxygen, and a single bond with hydrogen. Oxygen has 6 valence electrons, forms a single bond with carbon, and has 2 lone pairs. This leads to a trigonal planar geometry around the carbonyl carbon and a bent molecular shape around the oxygen atom.
10. HCN (Hydrogen cyanide)
* Shape: Linear
* Reasoning: Carbon has 4 valence electrons and forms a triple bond with nitrogen and a single bond with hydrogen. This leads to a linear structure.
11. H₂O₂ (Hydrogen peroxide)
* Shape: Non-planar, with each oxygen atom having a bent shape.
* Reasoning: Each oxygen atom has 6 valence electrons and forms a single bond with another oxygen atom and a single bond with a hydrogen atom. This leads to a bent shape around each oxygen atom due to the presence of two lone pairs. The overall molecule is non-planar due to the rotation around the oxygen-oxygen bond.
