“Counting drops and observing color”: Teachers’ and students’ first experiences in small-scale chemistry practicum of acid-base solutions

This study introduces a small-scale chemistry practicum technique with the concept of acid-base identification, determination of pH with indicators, and neutralization reactions with the concept of titration. The first experiences of teachers and students in small-scale chemistry practicums are revealed. Action research was carried out to introduce small-scale chemistry (SSC) practicum techniques as solutions for minimizing chemical tools and materials, as well as the availability of space for school chemistry practicums. This study involved 26 teacher participants in the initial process of providing experience and 36 student participants involved in the process of organizing practical classes. Quantitative data including teacher responses and student responses to the SSC practicum in the pilot class were collected using a response questionnaire on the activity. Qualitative data were collected through observation, interviews, and documentation. The practicum involves qualitative observations and quantitative calculations. The qualitative aspect relates to the observation of color changes that occur in a mixture of solutions made of acid and base solutions with certain compositions. Teachers get a lot of inspiration in terms of chemistry practicum with less material requirements, as well as modifying the tools used for laboratory activities. The package of tools and materials provided an illustration for them that practicum activities do not have to be carried out in a laboratory room, but can also be practiced in conventional classrooms, and even carried out independently by students at home. Students have a unique experience in the process of counting the number of droplets as it requires careful concentration and observationPeer Reviewe

Synthesis of new amines for enhanced carbon dioxide (CO2) capture performance: The effect of chemical structure on equilibrium solubility, cyclic capacity, kinetics of absorption and regeneration, and heats of absorption and regeneration

This work focused on the synthesis of new tertiary amines by varying the alkyl chain length with/without hydroxyl group in the structure. The effect of chemical structure of newly synthesized tertiary amines; 4-(dimethylamino)-2-butanol (DMAB), 4-(dipropylamino)-2-butanol (DPAB), 4-(dibutylamino)-2-butanol (DBAB), 4-((2-hydroxyethyl)(methyl)amino)-2-butanol (HEMAB) and 4-((2-hydroxyethyl)(ethyl)amino)-2-butanol (HEEAB) were evaluated based on CO2 equilibrium solubility and cyclic capacity, as well as rates and heats of CO2 absorption and regeneration. The results showed that three amines (i.e. DMAB, HEMAB and HEEAB) had the highest CO2 absorption capacity (0.88, 0.44 and 0.68 mol CO2/mol amine at 313 K temperature and 15 kPa CO2 partial pressure), and cyclic capacity (0.52, 0.26 and 0.40 at 313-353 K temperature range, 15 kPa CO2 partial pressure). These amines also had fast CO2 absorption rate (0.082, 0.111 and 0.142 mol CO2/min) and CO2 regeneration rate (0.512, 0.452 and 0.295 mol CO2/min) while maintaining low heat of CO2 absorption (-34.17, -56.21 and -69.79 kJ/mol CO2) and heat input of CO2 regeneration (39.73, 60.48 and 72.44 kJ/mol CO2). Based on these results, DMAB, HEMAB, and HEEAB can be considered to be promising amine components for blending for a post combustion CO2 capture process. 2016 Elsevier B.V. All rights reserved.The financial support from Overseas Research Experience Scholarship for Graduate Students , Graduate School at Chulalongkorn University is acknowledged. Supports from Clean Energy Technologies Research Institute - CETRI (previously known as International Test Center for CO 2 Capture - ITC) at the University of Regina are gratefully acknowledged for providing research facilities throughout this work. In addition, our team would also like to acknowledge the financial support in parts of this work provided by an NPRP Grant # 7-1154-2-433 from the Qatar National Research Fund (a member of Qatar Foundation).Scopu