For #"pentamminechlorochromium(III+) nitrate"#...can you...?

#"a. Give the d-electron count at the transition metal centre."#
#"b. Predict the spin state of the d-electrons."#
#"c. Identify the outer sphere ions?"#
#"d. Predict whether the complex is paramagnetic,"#
#"e. Give a possible coordination sphere isomer."#

1 Answer
Jan 8, 2016

Answer:

We start with a #Cr^(3+)# metal ion, that is surrounded by (coordinated to) 6 ligands in an octahedral array, to give #[Cr(NH_3)_5Cl]^(2+)(NO_3^-)_2#

Explanation:

a. The transition metal ion #Cr^(3+)# has a #d^3# electron count at the metal centre.
b. These #d^3# electrons are all unpaired.
c. The outer sphere ligands are reasonably the nitrate counter ions; as written the nitrates are not coordinated to the metal.
d. The complex is certainly a paramagnet. How do I know this?
e. For a coordination sphere isomer, simply replace one of the octahedrally coordinate ligands (ammine or chloro) with the counter ion, nitrato: i.e. #[Cr(NH_3)_5(NO_3)]^(2+)#.