TPR General Chem Passage 28 #3

[letsgoblue2015]

Which one of the following transition metal oxides is NOT colored?

A) CuO
B) FeO
C) TiO2
D) Mn2O3

Answer is C

The passage says transition elements show color because they have partially filled d orbitals. Therefore, I chose A because the d orbital exception makes Copper's d orbital fully filled.

Am I right or wrong here?

---

Members don't see this ad.

 

[AureatEagle]

Which one of the following transition metal oxides is NOT colored?

A) CuO
B) FeO
C) TiO2
D) Mn2O3

Answer is C

The passage says transition elements show color because they have partially filled d orbitals. Therefore, I chose A because the d orbital exception makes Copper's d orbital fully filled.

Am I right or wrong here?

Copper in CuO is Cu2+, which means it's missing its 4s electrons. Thus, it cannot promote any electrons into a d orbital to make its d shell completely filled. Cu2+'s electron configuration, in other words, is [Ar]4s0, 3d9.

 

[letsgoblue2015]

Why does it lose the s electrons and not the d ones?

 

[sakabato93]

The two 4s electrons are higher in energy than the 3d electrons, so they are transferred first. Now, d electrons begin transferring after all of the 4s electrons are gone. So for transition cations with 3+ charges, or higher, d electrons are involved, I believe.

 

[letsgoblue2015]

So since Titanium would have no d electrons when bonding to O, it's colorless?

 

[AureatEagle]

Correct!