Question

Which element of group 14 decomposes steam to form dioxide and dihydrogen gas?

• A. C
• B. Pb
• C. Ge
• D. Sn

Hint:

Remember the reactivity series of metals with steam. Elements that are more electropositive than hydrogen can reduce steam to hydrogen gas, forming their oxides. The reactivity generally increases down a group for heavier p-block elements due to the inert pair effect becoming more prominent for the lower elements. However, in this specific case, Tin shows a notable reaction with steam under heating.

Answer 1

The Correct Option is D

Step 1: Identify the elements of Group 14.
The elements are Carbon (C), Silicon (Si), Germanium (Ge), Tin (Sn), and Lead (Pb).
Step 2: Consider the reaction with steam.
The reaction involves the formation of the dioxide of the element and dihydrogen gas.
Step 3: Evaluate the reactivity of each element with steam.
Carbon reacts with steam to form CO or $CO_2$ and $H_2$ at high temperatures.
Silicon reacts with steam at high temperatures to form $SiO_2$ and $H_2$.
Germanium reacts with steam at high temperatures to form $GeO_2$ and $H_2$.
Tin reacts with steam at high temperatures to form $SnO_2$ and $H_2$. Lead is generally unreactive with steam.
Step 4: Determine the most appropriate element.
While C, Si, Ge, and Sn can react with steam to form their dioxides and dihydrogen, Tin shows a significant reaction under elevated temperatures.
Thus, the element is $ \boxed{Sn} $.