Silicon dissolves in excess of HF due to formation of: — p Block Elements Chemistry Question

💡 Solution & Explanation

Step 1: Silicon initially reacts with hydrofluoric acid (HF) to form gaseous silicon tetrafluoride (SiF4). Step 2: In the presence of excess HF, the formed SiF4 coordinates further with HF to produce a highly stable coordination complex. Step 3: The reaction is: Si + 6HF -> H2SiF6 + 2H2. The resulting compound is hexafluorosilicic acid (H2SiF6), which matches option (c).