Question

Which of the following can not react directly with halogens under suitable conditions?

• A. C
• B. Si
• C. Ge
• D. Pb

Answer 1

The correct option is A C

Except C all other elements of group 14 react directly with halogen under suitable conditions to form halides of formula $M{X}_2$ and $M{X}_4$.
Hence, the correct answer is option (a).

THEORY
$\Rightarrow$Reactivity towards oxygen:
All members when heated in oxygen form oxides
The acidity of oxides in higher oxidation states is greater than the acidity of oxides
in lower oxidation states.
$C{O}_2,Si{O}_2$ and $Ge{O}_2$ are acidic in nature. $Sn{O}_2\text{and}Pb{O}_2$ are amphoteric in nature. GeO is acidic, CO is neutral. SnO and PbO are amphoteric in nature.

$\Rightarrow$Reactivity towards water:
Carbon, silicon, and germanium are not affected by water.
Tin decomposes steam to form dioxide and dihydrogen gas.
$Sn+2H_{2}O\stackrel{△}{\to }Sn{O}_2+2H_2$
Lead is unaffected by water, due to the protective oxide film formation.

$\Rightarrow$Reactivity towards halogen:
These elements can form halides of formula $M{X}_2$ and $M{X}_4$ where X = F, Cl, Br, I
Except for C, all other elements react directly with halogen under suitable conditions to form halides.
Except $Sn{F}_4$ & $Pb{F}_4$ most of the $M{X}_4$ are covalent in nature.
The central atom in the halides is $s{p}^3$ hybridized and the molecule is tetrahedral in shape.
$Pb{I}_4$ doesn’t exist.