Question

Which of the following has CORRECT order of their indicating properties?

• A. $F-\hat{C}-F\left(C{H}_2{F}_2\right)>H-\hat{C}-H\left(C{H}_4\right);$ bond angle
• B. $H_{3}C-Cl>F_{3}C-Cl$; bond length of C-Cl
• C. $(C{H}_3{)}_{3}N>(Si{H}_3{)}_{3}N$; basic strength
• D. $P{H}_3>P{F}_3$; bond angle.

Answer 1

The correct option is A $F-\hat{C}-F\left(C{H}_2{F}_2\right)>H-\hat{C}-H\left(C{H}_4\right);$ bond angle

Band angle depend on % $S-$ character by relation $\cos \theta =\frac{S}{S-1}$ $\therefore S=$% character

$\therefore \theta \alpha$ %S $\therefore \theta =$ bond angle

and more electronegative atom like Flumine $\left(F\right)$ requires less $S-$ character as a result $F-P-F$ has less $S-$ character or less bond angle and $H-P-F$ bond required more $S-$ character since ${}^{\prime }{H}^{\prime }$ is less electronegative than $F$. So, bond angle in $H-P_{F}l$ is more.

Similarly we can explain for ${CH}_4\&{CH}_2{F}_2$.