Question

Which one of the following is incorrect?
A] The bond order of $\mathop H\nolimits_2 $, $\mathop N\nolimits_2 $ and $\mathop O\nolimits_2 $ follows the order $\mathop N\nolimits_2 $>$\mathop O\nolimits_2 $ > $\mathop H\nolimits_2 $
B] In $CsCl$ lattice, each $Cs$ is surrounded by $\mathop {BCl}\nolimits^ - $ ions
C] The ionic nature of $KCl$, $\mathop {Mgcl}\nolimits_2 $ and $\mathop {AlCl}\nolimits_3 $ follows the order $KCl$ >$\mathop {Mgcl}\nolimits_2 $ > $\mathop {AlCl}\nolimits_3 $
D] The central atom of $\mathop {PF}\nolimits_5 $, $\mathop {ClF}\nolimits_5 $, and $\mathop {XeF}\nolimits_2 $ have $\mathop {Sp}\nolimits^3 d$ hybridization.

Answer 1

Hint: In diatomic molecules, bond order is usually defined as the number of bonds formed between the two atoms. The ionic nature of a substance increases as the charge on it increases. Lattice is defined as the arrangement of atoms in the form of regular arrangement.

Complete step by step answer: A] The bond order of $\mathop H\nolimits_2 $, $\mathop N\nolimits_2 $and $\mathop O\nolimits_2 $ follows the order $\mathop N\nolimits_2 $>$\mathop O\nolimits_2 $ > $\mathop H\nolimits_2 $:- as there are single bond present between dihydrogen $\mathop H\nolimits_2 $ it has bond order 1 , $\mathop N\nolimits_2 $ has three bonds between them so has bond order 3 and $\mathop O\nolimits_2 $ with two bonds have bond order 2. So $\mathop N\nolimits_2 $>$\mathop O\nolimits_2 $ > $\mathop H\nolimits_2 $. So this statement is not wrong.

B) In $CsCl$ lattice, each $Cs$ is surrounded by $\mathop {BCl}\nolimits^ - $ ions: - $CsCl$ has body centered cubic arrangement. It has coordination number 8. Thus each Cs is surrounded by $8Cl$. Hence this statement is not wrong.

C) The ionic nature of $KCl$, $\mathop {Mgcl}\nolimits_2 $ and $\mathop {AlCl}\nolimits_3 $ follows the order $KCl$ >$\mathop {Mgcl}\nolimits_2 $ > $\mathop {AlCl}\nolimits_3 $
:- potassium has 1 electron in its outer shell as its atomic mass is 19 so electronic configuration 2,8,8,1 so has 1 unit charge. Magnesium has 2 unit charge and aluminum has 3 unit charge. So the order should be reversed $KCl$ >$\mathop {Mgcl}\nolimits_2 $ > $\mathop {AlCl}\nolimits_3 $. Hence this option is not correct.

D] The central atom of $\mathop {PF}\nolimits_5 $, $\mathop {ClF}\nolimits_5 $, and $\mathop {XeF}\nolimits_2 $ have $\mathop {Sp}\nolimits^3 d$ hybridization: - in $\mathop {PF}\nolimits_5 $ it involves three p one s and one d orbital thus have sp3d hybridization. In $\mathop {ClF}\nolimits_5 $ it involves 2 lone pair and three bonds and in $\mathop {XeF}\nolimits_2 $ three lone pair and two bond pair so have $\mathop {Sp}\nolimits^3 d$ configuration. So, this option is wrong as this statement is correct.

Note: When charge on an atom increases it becomes more ionic. The charge depends on the valence shell electrons. Potassium has 1 electron in its outer shell as its atomic mass is 19 so electronic configuration 2,8,8,1 so has 1 unit charge. Magnesium has 2 unit charge as atomic number 12 and configuration 2,8,2 so it can donate 2 electrons and aluminum has 3 unit charge.