MHB Explaining Copper(2) Oxide Bonding & ECs

[markosheehan]

Could someone explain the bonding of copper(2) oxide to me? What are each element's EC before and after?

i understand the copper has a variable valency and in this case it looses 2 electrons to make the overall charge 0. however i don't understand the electron configurations. coppers EC before is 2,8,8,8,3. it looses 2 electrons so it goes to 2,8,8,8,1 this is not stable and this doesn't make sense to me.

 

[Joppy]

The abbreviation EC has quite a few meanings in chemistry, can you be more clear about it please.

Anyway, copper (II) is a bit of an exception from memory. Try searching for why Cu(II) is stable.

 

[I like Serena]

Could someone explain the bonding of copper(2) oxide to me? What are each element's EC before and after?

i understand the copper has a variable valency and in this case it looses 2 electrons to make the overall charge 0. however i don't understand the electron configurations. coppers EC before is 2,8,8,8,3. it looses 2 electrons so it goes to 2,8,8,8,1 this is not stable and this doesn't make sense to me.

Hi markosheehan,

I'm assuming EC stands for Electron Configuration?

Before the bonding Copper has the configuration 2-8-18-1 (there are 18 electrons in the M valence shell) and Oxygen has 2-6.
After the bonding Copper has 2-8-17 and Oxygen has 2-8.

And indeed Copper doesn't have a 'nice' full shell.
There are some complicated answers out there about why that is, but long story short, in this particular case Copper(II) Oxide is more stable than Copper(I) Oxide.

 

[markosheehan]

thanks I like serena . that's what i was looking for.

i thought when bonding takes place atoms always want full outer shells? are there exceptions?

 

[Dethrone]

thanks I like serena . that's what i was looking for.

i thought when bonding takes place atoms always want full outer shells? are there exceptions?

There are many exceptions. I remember back in my first year chemistry course, my professor criticized the textbook for providing incorrect explanations to these exceptions. Most of the time these explanations go much beyond the scope of general chemistry courses, so I wouldn't worry about them.

 

[I like Serena]

thanks I like serena . that's what i was looking for.

i thought when bonding takes place atoms always want full outer shells? are there exceptions?

Yes, there are exceptions.
Most elements have a stable bonding with a full outer shell, but they typically also have alternative stable bondings.
For instance $CO$ and $CO_2$ are both stable, and $CO_2$ is the one where $C$ has a full outer shell.
Copper is apparently one of the exceptions where the bonding with a full outer shell ($Cu^+$) is less stable than other bondings ($Cu^{2+}$ and $Cu^{3+}$). Note that Copper also has a stable Copper(III) Oxide binding.