The instructional method “problem-solving by means of experiments” is applied by a group of students to the case of collection and measurement of the volume of carbon dioxide in a coca-cola bottle. In the context of collaborative learning, through a line of proposals and dialogue with the instructor, the group tries to suggest an experimental device that would give solution to the problem. Despite the difficulties, the final result shows a positive attitude of the students; in addition, the overlap of theory, experiment and the scientific method seems to create a perspective for a improvement of the instructional methods in the teaching of science.