Are these shapes correct?PH3-trigonal pyramidal, CHCl3-tetrahedral, H2S-linear and PO4^-3-tetrahedral?

When you say shape do you refer to the electronic geometry or the molecular geometry. I assume molecular geometry. PH3, CHCl3 and PO4^3- are correct. H2S is angular (like water).

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Got it! H2S is bent. Thank you!

To determine the correct shapes of these molecules, we need to consider their molecular geometries based on the number of electron groups around the central atom.

1. PH3 (Phosphine):
- Phosphine (PH3) has a central phosphorus atom bonded to three hydrogen atoms.
- To determine its shape, we count the number of electron groups around the central atom, which in this case is four (three bonding pairs and one lone pair).
- The electron group arrangement is tetrahedral.
- Since there is one lone pair present, the molecular shape of PH3 is trigonal pyramidal.

2. CHCl3 (Chloroform):
- Chloroform (CHCl3) has a central carbon atom bonded to three hydrogen atoms and one chlorine atom.
- Again, we count the number of electron groups around the central atom, which is four (three bonding pairs and one lone pair).
- The electron group arrangement is tetrahedral.
- As there are no lone pairs present, the molecular shape of CHCl3 is also tetrahedral.

3. H2S (Hydrogen sulfide):
- Hydrogen sulfide (H2S) has a central sulfur atom bonded to two hydrogen atoms.
- Counting the number of electron groups around the central atom gives us two (two bonding pairs).
- The electron group arrangement is linear.
- Thus, the molecular shape of H2S is linear.

4. PO4^-3 (Phosphate):
- The phosphate ion (PO4^-3) has a central phosphorus atom bonded to four oxygen atoms.
- Counting the number of electron groups around the central atom gives us five (four bonding pairs and one lone pair).
- The electron group arrangement is trigonal bipyramidal.
- With one lone pair, the molecular shape of PO4^-3 is tetrahedral.

To summarize:
- PH3 is trigonal pyramidal.
- CHCl3 is tetrahedral.
- H2S is linear.
- PO4^-3 is tetrahedral.