This paper proposes an experiment
in which students build microdevices
for conveniently electrolyzing water and use image recognition and
processing technology to measure the volume of gas generated during
the reaction in a noncontact way. Taking advantage of three ratio
relationships between (i) gas volume and the area of bubbles, (ii)
the factual size and the size on the picture, and (iii) the area on
the picture and the pixel number, the experiment converts the measurement
of trace gas volume into measurement of bubbles’ pixel number
on the picture, which simplifies the complex problem. The device includes
pencil refills as the electrodes, compressing the reaction space in
the interval between two glass slides to squeeze the gas generated
into flat-cylinder shaped bubbles with a fixed height. The students
use a smartphone to take pictures and use software to process the
images. Briefly, edges of bubbles are recognized and enhanced by PowerPoint,
followed by a cutout process by Photoshop to get the bubbles’
image without the background; a histogram tool is then used for analyzing
the pixel number of bubbles to finally get the volume of hydrogen
and oxygen. Results of the survey among participating students proved
the pedagogical effectiveness of this project.
The practice and research on online chemistry education have received great attention in the context of the COVID-19 pandemic worldwide. This paper describes the teaching practice of online learning based on three online courses for pre-service chemistry teachers. To adapt online teaching requirements, we reshaped the structure of the physical chemistry course, for example, adjusting the assessment approaches, and reinforcing long-distance instruction. Besides, we also shared the course of training chemistry teaching skills online publicly, and provided multiple learning approaches after class. Moreover, we introduced chemistry education research based on website data in an educational research methods course and shared ideas through the technology platform.
This study developed a complexometric
titration simulation program
based on LabVIEW. With built-in approximation and rigorous algorithms,
the program can easily simulate and plot a single or a group of complexometric
titration curves. On the basis of this program, we developed and implemented
an online course to guide undergraduates to (i) compare the differences
between the two titration types EDTA (Y) to Metal (M) and M to Y,
(ii) explore the influencing factors of a titration jump, (iii) explore
the conditions for an accurate titration, and (iv) find evidence for
the existence of complexometric equilibrium. Questionnaires from 25
students were used for evaluation. The results showed that the program
had high usability, practicability, effectiveness, and user behavior
intention. Besides, 92% of the students were willing to use it more
in the future and 11 students completed the test with an average score
of 124.6 (full score of 150), and the average score of the modules
corresponding to each learning goal was high, indicating that the
students had achieved satisfactory learning outcomes.
To promote the integration of aesthetic
education into chemistry
education, this study designed activities to photograph precipitation
reaction experiments with a smartphone, thereby combining experimental
inquiry with artistic creation across disciplines. These activities
were divided into (i) perceiving, (ii) appreciating, (iii) exploring,
and (iv) creating the beauty of chemistry. The participants first
used macrophotography to capture the details and small changes of
a precipitation reaction to obtain an impression of beauty. Then,
they managed to understand, appreciate, and evaluate the beauty of
the precipitation reaction from an artistic vision (admiring chemistry
like an artist). Next, the students explored the fascinating phenomenon
from a chemical perspective and looked for its inherent laws. Finally,
they consistently improved the experimental and photographic methods
and created works of scientific photography. These activities are
suitable for students from primary school to college, and even for
the general public. The experiments can be completed in only 1 min,
but several hours can be spent to improve the results. In the end,
most students are able to take high-quality photographs of precipitation
reactions.
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