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Mercury I Chloride, Ionic or Covalent?

Hi

Is Mercury I Chloride, Ionic or Covalent?

I've heard one person say that Hg2Cl2 involves two Hg ions with 1+ charge. And is ionic.

Another said Hg2 is a polyatomic ion with 2+ charge.. that makes sense and I see https://en.wikipedia.org/wiki/Mercury(I)_chloride says it's known as Mercurous Chloride. So that would mean it's ionic.

But that wikipedia article doesn't say anything about a cation and an anion, and says "Hg2Cl2 is a linear molecule". So that suggests covalent molecular. 'cos the term molecule is used with covalent entities.

And i'm not sure if there are other hints too there that it's covalent.

So i'm puzzled really, if it's ionic or covalent?

Thanks
Original post by gazbo1
Hi

Is Mercury I Chloride, Ionic or Covalent?

I've heard one person say that Hg2Cl2 involves two Hg ions with 1+ charge. And is ionic.

Another said Hg2 is a polyatomic ion with 2+ charge.. that makes sense and I see https://en.wikipedia.org/wiki/Mercury(I)_chloride says it's known as Mercurous Chloride. So that would mean it's ionic.

But that wikipedia article doesn't say anything about a cation and an anion, and says "Hg2Cl2 is a linear molecule". So that suggests covalent molecular. 'cos the term molecule is used with covalent entities.

And i'm not sure if there are other hints too there that it's covalent.

So i'm puzzled really, if it's ionic or covalent?

Thanks

Whether a molecule is covalent or ionic depends on the difference in electronegativity
The border between covalent and ionic is not strict
See https://chemistry.stackexchange.com/questions/16261/metal-compounds-that-bond-covalently
‘Mercury(I) exists in solution as [Hg2]2+ where the two mercury ions are covalently bonded.’
(edited 7 months ago)
Reply 2
I know covalent--ionic is a spectrum and on one end there's purely covalent / 100% covalent, eg Cl2, to non polar covalent, to polar covalent, to predominently ionic, and nothing is 100% ionic. And there are ranges based on percentage of ionic character, that can be used for these classifications. When we say ionic, it means predominently ionic. Percentage of ionic character is a bit more complex of a calculation than "difference in electronegativity".

It's reasonable to ask if a compound is ionic by which is meant, predominently ionic. OR if it's covalent, e.g. be it non polar covalent, or polar covalent.
Reply 3
Original post by gazbo1
Hi

Is Mercury I Chloride, Ionic or Covalent?

I've heard one person say that Hg2Cl2 involves two Hg ions with 1+ charge. And is ionic.

Another said Hg2 is a polyatomic ion with 2+ charge.. that makes sense and I see https://en.wikipedia.org/wiki/Mercury(I)_chloride says it's known as Mercurous Chloride. So that would mean it's ionic.

But that wikipedia article doesn't say anything about a cation and an anion, and says "Hg2Cl2 is a linear molecule". So that suggests covalent molecular. 'cos the term molecule is used with covalent entities.

And i'm not sure if there are other hints too there that it's covalent.

So i'm puzzled really, if it's ionic or covalent?

Thanks


OP wrote "Is Mercury I Chloride, Ionic or Covalent?"

Covalent


OP wrote "I've heard one person say that Hg2Cl2 involves two Hg ions with 1+ charge. And is ionic. Another said Hg2 is a polyatomic ion with 2+ charge.. that makes sense and I see https://en.wikipedia.org/wiki/Mercury(I)_chloride says it's known as Mercurous Chloride. So that would mean it's ionic."

The terminology is a big mess. It's a misnomer to say mercurous ion there. Maybe historicall they thought it was an ionic compound. There is a mercurous ion in mercury(I) Nitrate though.

Mercury(I) Nitrate is ionic. But Mercury(I) Chloride is covalent. No Ions.

OP writes "But that wikipedia article doesn't say anything about a cation and an anion, and says "Hg2Cl2 is a linear molecule". So that suggests covalent molecular. 'cos the term molecule is used with covalent entities."

Yeah it's covalent. The Hg-Hg bond is covalent. And the Hg-Cl bonds are covalent(probably polar covalent, but covalent).

OP writes "And i'm not sure if there are other hints too there that it's covalent." <-- I've heard somebody mentioned the bond length.. and the melting point or sublimation ponit.. And besides the word molecule in the crystal.. But the fact that the term "linear" is used also with the word molecule. Linear is a direction.. Only covalent bonds are directional.

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