Classify hydrogen fluoride as either a molecular or ionic compound and describe a chemical test that could be done to prove that hydrogen fluoride is acidic? 

Expert Answers

An illustration of the letter 'A' in a speech bubbles

HF or hydrogen fluoride is also called hydrofluoric acid.  It is composed of the proton cation (H+) and the fluoride anion (F-).  Fluorine is the most electronegative element on the periodic table and as such readily forms the fluoride anion.  Such a large degree in electronegativity difference between fluorine and hydrogen...

Unlock
This Answer Now

Start your 48-hour free trial to unlock this answer and thousands more. Enjoy eNotes ad-free and cancel anytime.

Start your 48-Hour Free Trial

HF or hydrogen fluoride is also called hydrofluoric acid.  It is composed of the proton cation (H+) and the fluoride anion (F-).  Fluorine is the most electronegative element on the periodic table and as such readily forms the fluoride anion.  Such a large degree in electronegativity difference between fluorine and hydrogen guarantees that the bond between then will be ionic.  A simple chemical test to prove the acidity of HF would be to add some HF to an aqueous solution of sodium bicarbonate (NaHCO3).  Sodium bicarbonate is a mild base and reacts with acids to produce carbonic acid (H2CO3) which breaks down into water and carbon dioxide.  So when you add HF to NaHCO3, you will see the carbon dioxide bubble out of solution, thus proving the acidity of HF.

Approved by eNotes Editorial Team