Abstract The new coronavirus pandemic (COVID-19) is a global problem that is having severe impacts on health systems worldwide. One particular characteristic of this virus is its high transmission rate, which has led to a high demand for personal care materials such as masks, gloves, and alcohol for asepsis. Seventy percent is the ideal concentration for the ethanol used in hand sanitizers; however, this concentration can be expressed in different ways, and, consequently, the different solutions will have different antiseptic activity. In this manuscript we comment on some characteristics of alcohol-based preparations and the different ways of expressing the concentrations.

Abstract The arrival of the COVID-19 pandemic imposed a series of restrictions on a global scale. A new social dynamic had to be adopted around the world, in an attempt to contain its effects. Teaching activities, as it could not be otherwise, also had to be adapted to totally virtual reality, as a result of the need for social distance. One of the main challenges was to implement virtual teaching in a way that reached the entire academic community. Since then, different methodologies have been adopted to meet the demands of the most varied contexts. In this manuscript we report the use of the flipped classroom methodology in two General Chemistry classes, adapted to the virtual modality, in the context of a Brazilian federal university. The students’ perception of the methodology and the tutorial work developed in one of the classes was evaluated. The results show that the flipped classroom can be adapted to fully virtual reality, being favored in various ways by tutoring work.

Resumen La llegada de la pandemia COVID-19 impuso una serie de restricciones a escala global. Una nueva dinámica social se tuvo que adoptar en todo el mundo, en un intento por contener sus efectos. Las actividades docentes, como no podía ser de otra manera, también tuvieron que adaptarse a la realidad totalmente virtual, como consecuencia de la necesidad de distanciamiento social. Uno de los principales desafíos fue implementar la enseñanza virtual de manera que llegara a toda la comunidad académica. Desde entonces, se han adoptado diferentes metodologías para satisfacer las demandas de los más variados contextos. En este texto reportamos el uso de la metodología flipped classroom (que se traduce como clase invertida) en dos asignaturas de Química General, adaptadas a la modalidad virtual, en el contexto de una universidad federal brasileña. Se evaluó la percepción de los estudiantes sobre la metodología y el trabajo de tutoría desarrollado en uno de los grupos. Los resultados muestran que el aula invertida se puede adaptar a la realidad totalmente virtual, siendo favorecida de diversas formas por el trabajo de tutoría.