The main objective of this research work is to recognize the implications of argumentation development to favor the learning of the stoichiometry concept in eleventh grade students; it is framed within a qualitative perspective with a descriptive character in order to characterize argumentative processes and products. Initially the students previous ideas were identified and the argumentative level and the quality of the students arguments were established, then a didactic unit divided into four moments was applied in order to promote the development of argumentation against the concept of stoichiometry; for six weeks, to finally assess the change in the argumentative levels and the quality of the students' arguments. Based on the five argumentative levels proposed by Tamayo (2011) and the three levels of quality of an argument raised by Marin (2018). The results obtained allowed establishing that there was a change in the argumentative levels and in the quality of the arguments of the students' arguments, reaching better-structured and higher-quality arguments regarding their functionality. In conclusion, it could be established that the development of argumentation to favor the learning of the stoichiometry concept, implies changes in the argumentative level and the quality of the arguments, and also allows, also a better use and understanding of the stoichiometry concept in the learning of eleventh grade students, when trying to respond to situations of the concept.