Question

The correct order of increasing $C-X$ bond length is:
($R$ is methyl group)

• A. $RI>RBr>RCl>RF$
• B. $RF>RCl>RBr>RI$
• C. $RBr>RCl>RI>RF$
• D. $RCl>RF>RI>RBr$

Answer 1

The correct option is A $RI>RBr>RCl>RF$

$C-X$ bond length totally depends on atomic size of halogens . The more is the size more will be bond length. The atomic size of halogens is $I>Br>Cl>F$. Hence, the correct order of increasing C-X bond length is $RI>RBr>RCl>RF$.