1. Write the formula for these compounds:
a) sodium tris(oxalato)rhodium(III)
b) sodium tetrachloroplatinate(II)
c) triamminetrichloronickel(IV) sulfate
For a) I put: Na3Rh(C2O4)3, however got an error message of this: "Your answer appears to be missing required square brackets." Is it just a matter of where the brackets are, or something wrong with the formula?
2. Which of the following ligands can be polydentate? If the ligand can be polydentate, give the maximum number of places on the ligand that can bind simultaneously to a single metal center.
(a) N(CH2CH2NH2)3
monodentate
polydentate, 2 bonds
polydentate, 3 bonds
polydentate, 4 bonds
polydentate, 5 bonds
polydentate, 6 bonds
polydentate, 7 bonds
polydentate, 8 bonds
I believe bracket designate the coordination sphere and the metal usually precedes the anion part of the coordination sphere.
Na3[Rh(C2O4)3]. Some would name it "trisodium" but that but I don't believe that is necessary
1. The correct formulas for the given compounds are:
a) sodium tris(oxalato)rhodium(III) - Na3[Rh(C2O4)3]
b) sodium tetrachloroplatinate(II) - Na2[PtCl4]
c) triamminetrichloronickel(IV) sulfate - [Ni(NH3)3Cl3]SO4
For part a), your initial formula Na3Rh(C2O4)3 was almost correct. However, in chemical formulas, coordination compounds are usually enclosed in square brackets "[ ]" to indicate the coordination complex. So the correct formula is Na3[Rh(C2O4)3]. Make sure you place the coordination complex portion of the formula inside the square brackets.
2. The ligand N(CH2CH2NH2)3 is referred to as tris(2-aminoethyl)amine. To determine its polydentate capabilities, we need to count the number of binding places or "binding sites" (also known as donor atoms, typically nitrogen or oxygen) that can simultaneously bind to a single metal center. Each amine group (NH2) in tris(2-aminoethyl)amine can serve as a donor atom.
In this case, since tris(2-aminoethyl)amine has three amine groups, it can bind simultaneously to a single metal center at a maximum of three places (with three nitrogen atoms). Therefore, the correct answer is "polydentate, 3 bonds."
Keep in mind that the maximum number of bonds a ligand can form is determined by the number of available donor atoms in the ligand molecule.