Which of the following statements are correct? I. $\mathrm{P}_4$ molecule is very reactive because of…
Which of the following statements are correct?
I. $\mathrm{P}_4$ molecule is very reactive because of angular strain.
II. The basicity of $\mathrm{H}_3 \mathrm{PO}_3$ is 3 .
III. In gas phase, all $\mathrm{P}-\mathrm{Cl}$ bonds of $\mathrm{PCl}_5$ have same bond length.
IV. In solid state, $\mathrm{PCl}_5$ exists as an ionic solid, in which anion $\left[\mathrm{PCl}_6\right]^{-}$has octahedral and cation $\left[\mathrm{PCl}_4\right]^{+}$has tetrahedral shape.
I and II
II and IV
I and IV
I and III
Solution
(II) The basicity of $\mathrm{H}_3 \mathrm{PO}_3$ is 2 , this is because out of the three hydrogen atoms only two are attached to most electronegative oxygen atom and can be removed.
(III) $\mathrm{PCl}_5$ structure is trigonal bipyramidal in which two axial $\mathrm{P}-\mathrm{Cl}$ bonds are longer than rest three equitorial $\mathrm{P}-\mathrm{Cl}$ bonds