Question

What is the IUPAC name of [AuCl4(H2O)2]-1? a)diaquatetrachloroaurate(0) b) diaquatetrachloroaurate(III) c)diaquatetrachloroaurate(I) d)diaquatetrachlorogold(III) e)diaquatetrachlorogold(I)

Other
What is the IUPAC name of [AuCl4(H2O)2]-1?
a)diaquatetrachloroaurate(0)
b) diaquatetrachloroaurate(III)
c)diaquatetrachloroaurate(I)
d)diaquatetrachlorogold(III)
e)diaquatetrachlorogold(I)

The overall charge of the ion is -1. What contributes to the charge? $$\displaystyle{C}{l}^{{-{}}}$$ and $$\displaystyle{A}{u}^{+}$$, where the Au is not yet determined. Charges must be arithmetically conserved. Four chlorideions provid 4(-1) = -4 charge. But the molecule is -1 net charge.Thus, Charge Au + charge Cl = -1. Charge from Aumust equal +3, since 3 + (-4) = -1. Thus the roman numeral associated with the metal cation must be III. So that eliminatesthe answer to b or d.