Question

Question: Silicon nitride resists all acids except hydrofluoric, with which it reacts to give silicon tetrafluoride and ammonia. Write a balanced chemical equation for this reaction.

Short answer

The balanced chemical equation for this reaction is,

${\mathrm{Si}}_3{\mathrm{N}}_4+12\mathrm{HF}\to 3{\mathrm{SiF}}_4+4{\mathrm{NH}}_3$

Step-by-step solution

Step 1:

Silicon nitride resists all acids except hydrofluoric but it is being attacked by dilute HF or hot HF.

Step 2:

The balanced chemical equation for this reaction is,

${\mathrm{Si}}_3{\mathrm{N}}_4+12\mathrm{HF}\to 3{\mathrm{SiF}}_4+4{\mathrm{NH}}_3$