Question

Among the following, which one is a wrong statement?

• A. $PH_5 $ and $BiCl_5$ do not exist
• B. $p\pi -d \pi$ bonds are present in $SO_2$
• C. $SeF_4$ and $CH_4$ have same shape
• D. $I^+_3 $ has bent geometry

Answer 1

The Correct Option is C

To determine which statement is incorrect, let's examine each one based on chemical knowledge:

1. $PH_5$ and $BiCl_5$ do not exist:
   • $PH_5$ does not exist because phosphorus cannot form five bonds in a stable manner due to limited availability of d-orbitals.
   • $BiCl_5$ does not exist because bismuth is too large and has inert pair effect limiting its oxidation states; primarily forms $BiCl_3$.
   • This statement is correct.
2. $p\pi -d\pi$ bonds are present in $SO_2$:
   • $SO_2$ does involve $p\pi -d\pi$ bonding between sulfur and oxygen.
   • This statement is correct.
3. $SeF_4$ and $CH_4$ have the same shape:
   • $CH_4$ (methane) has a tetrahedral shape with bond angles of approximately 109.5 degrees.
   • $SeF_4$ has a seesaw shape due to the presence of a lone pair, resulting in different bond angles.
   • This is incorrect as both molecules do not share the same shape.
4. $I^+_3$ has bent geometry:
   • $I^+_3$ typically has linear geometry as it forms a chain with iodine atoms.
   • This statement is correct as it specifically refers to the cation not changing the linear arrangement.

Therefore, the incorrect statement is: "$SeF_4$ and $CH_4$ have the same shape" because these compounds have different molecular geometries.