Which of the following produces a coordinate complex?
H2SeO4 + 2Cl- + 2H+ --> H2SeO3 + Cl2 + H2O
S8 + 8O2 --> 8SO2
3Br2 + 6OH- --> 5Br- + BrO3- + 3H2O
Ca+2 + SO4-2 -->CaSO4
PtCl4 + 2Cl- --> PtCl6(-2)
Pt is the most likely choice.
To determine which of the given chemical equations produces a coordinate complex, we need to identify the equation that involves a transition metal complex. Transition metals are capable of forming coordinate complexes in which they donate electron pairs to ligands.
Let's analyze each equation to identify any transition metal complexes:
1. H2SeO4 + 2Cl- + 2H+ --> H2SeO3 + Cl2 + H2O
This equation does not involve any transition metals or ligands. It is a redox reaction involving the transfer of electrons between species.
2. S8 + 8O2 --> 8SO2
This equation does not involve any transition metals or ligands. It is a combustion reaction in which sulfur reacts with oxygen to form sulfur dioxide.
3. 3Br2 + 6OH- --> 5Br- + BrO3- + 3H2O
This equation does not involve any transition metals or ligands. It is a redox reaction where bromine reacts with hydroxide ions to form bromide ions and bromate ions.
4. Ca+2 + SO4-2 --> CaSO4
This equation does not involve any transition metals or ligands. It is an ionic reaction where calcium ions combine with sulfate ions to form calcium sulfate.
5. PtCl4 + 2Cl- --> PtCl6(-2)
This equation involves the transition metal platinum (Pt) and ligands (chloride ions, Cl-). The formation of PtCl6(-2) is an example of a coordinate complex, where platinum donates electron pairs to chlorine ligands, resulting in a six-fold coordination.
Therefore, the answer is PtCl4 + 2Cl- --> PtCl6(-2) as it produces a coordinate complex.