Task: Question Answering
Input (English): Question: Ethylenediaminetetraacetic acid (EDTA) is a chelating agent widely used as a titrator in complexometric assessments that are characterized by: 
 Options:  <1> To make possible the EDTA titration of many metals in alkaline solutions an auxiliary complexing agent is used which prevents the metal ion from precipitating as hydroxide. <2> EDTA forms complexes of 1: 2 stoichiometry with some metal ions and therefore has a poor application in quantitative analysis. <3> It is important to choose an adequate pH to carry out the titration because metal-EDTA complexes are more stable at low pH than at high pH. <4> When evaluating a metal ion with EDTA, there is an excess of EDTA at the equivalence point. <5> When evaluating a metal ion with EDTA, there is an excess of metallic ion at the equivalence point.
Output (English): 1