Understanding Of Acid Research Articles

The persistence of primary school students’ initial ideas about acids and bases in the mental models of adults

The paper describes our research aimed to verify the durability of pupils' initial ideas and concepts on the issue of acids and bases. First, we mapped their existence among primary school pupils and then compared them with the ideas of secondary and university educated adults. It has been confirmed that some initial ideas are very lasting and are also reflected in the understanding of acids and bases in adults. By comparing these results we identified which initial ideas were overcome by education and which persisted.

Scaffolding in Learning Cycle 5E, is it Effective or Not?

Learning chemistry in the chemistry education study program has not maximized the scaffolding provision yet, so students still have difficulty in mastering the precondition concept. This study aims to determine the effectiveness of learning using the 5E learning cycle model assisted by scaffolding on acid and base material as seen from an increase in students' understanding of concepts. This research is a quasi-experiment with one group pretest-posttest design. The subjects of this study were 32 students who choose randomly from the chemical education study program class of 2019. The instrument used is an essay learning achievement test to measure students' understanding of acid and base concepts. The results showed that the n-gain value obtained is 0.31 or can be interpreted as an increase with moderate criteria. Therefore it can be concluded that the addition of scaffolding in the 5E learning cycle is effective to increase students' understanding on acid and base material.

Using Think-Pair-Share to Develop Students' Social and Emotional Competencies in Chemistry Learning

<p>The aim of this study was to analyze students' social and emotional competencies through the integration of Think Pair Share (TPS) and a Social and Emotional Learning (SEL) approach to topics related to Ac­ids and Bases. Social and emotional learning (SEL) is the process through which children and adults under­stand and manage emotions, set and achieve positive goals, feel and show empathy for others, establish and maintain positive relationships, and make responsible decisions.. The study involved thirty-five 11th grade students in one of private school in Jakarta and was conducted between January and April, 2017. A qualitative methodology was employed to analyze students’ social and emotional competencies using inter­views, classroom observations, reflective journals, and student worksheets. The application of a SEL ap­proach was carried out by integrating it with a TPS strategy. In the <em>Think</em> stage students were given the opportunity to explore their understanding of acids and bases and to solve problems individually. In the<em> Pair</em> stage they could communicate their insights to the group, and in the <em>Share</em> stage they had occasion to present their group perspectives and respond to others. The five social and emotional competences found in this study were; self awareness, self management, social awareness, relationship management, and re­sponsible decision making. Self awareness was demonstrated by understanding a student’s abilities, their needs, and their self- confidence. Self management was indicated by a student’s ability to manage pressure, plan strategies, and seek help. Social awareness competencies were analyzed through the development of students' attitudes to diversity and how they demonstrated care for friends. Relationship management com­petencies were identified by observing a student’s ability to manage friendships, how they overcame differ­ences, and whether they provided assistance to each other. The responsible decision making competency was determined by observing how students made decisions when trying to solve a problem and whether they were able to plan a strategy when facing pressure. Whilst integrating SEL the researchers were chal­lenged by the need to empower students, encourage teachers to stimulate students’ social and emotional competencies, and to manage time constraints. Integrating SEL into chemistry learning provided opportuni­ties for students to develop their social and emotional competencies through independent thinking activities, group discussions, and presentations to their peers.</p>

Does Learner-Centred Approach Improve High School Learners’ Understanding of Acids and Bases Topic? A Case of Two Selected Secondary Schools in Ohangwena Region, Namibia

This paper presents findings on a study that was conducted at two selected secondary schools in Ohangwena educational region in Namibia. The study used a quantitative approach to investigate if using learner-centred approach improves learners’ understanding of acids and bases. With a sample of 80 grade 11 learners taking Physical Science Ordinary level, a quasi-experimental design was used to collect data from two schools for two weeks (one week at each school). The Pre-test, post-test scores from the control group consisting of 40 learners from school A and an experimental group of 40 learners from school B were used to establish the cause and effect relationship between the use of Learner-Centred Approach (LCA) and learners’ understanding of acids and bases based on their performance in the tests were given. Descriptive statistics was used to analyse the quantitative data from the tests cores and a t-test analysis was conducted for both groups. The study results indicated that the experimental group performed better than the control group. It also emerged that using various learner-centred activities attracted learners’ interests in learning and understanding acids and bases. It is therefore concluded that learner-centred approaches improved high school learners’ understanding of the topic acids and bases. The study recommends that Physical Science teachers should make the teaching and learning of acids and bases more practical-based by using learner-centred approaches.

Understanding Acid and Base Concepts among Chemistry and Biology Pre-service Teachers at Faculty of Education in Amran University–Yemen

هدفت هذه الدراسة إلى معرفة فهم معلمي الكيمياء والأحياء اليمنيين قبل الخدمة (YCBPSTs) لمفاهيم الأحماض والقاعدة. تحقيقا لهذه الغاية ، أجريت دراسة مقطعية على عينة تتكون من 246 موضوع تم اختيارهم من 590 من CBPSTs المسجلين في برنامج إعداد معلمي العلوم قبل الخدمة (SPSTs) في كلية التربية جامعة عمران في اليمن. تم تطوير اختبار القاعدة الحمضية ، 24 سؤالًا متعدد الخيارات ، كأداة لإجراء هذه الدراسة. تم حساب صلاحية المحتوى وكذلك موثوقية الأداة. وجد أن معامل ألفا كرونباخ للأداة يساوي (0.72). كشفت نتائج هذه الدراسة أن الدرجات الإجمالية لجميع المشاركين كانت منخفضة. ومن هنا كانت النسب المئوية لمتوسط ​​الدرجات التي تم تحقيقها في اختبار القاعدة الحمضية الشاملة ومقاييسها لجميع المشاركين على التوالي (38٪ ، 40٪ ، 36٪ ، 36٪). بالإضافة إلى عدم وجود فروق ذات دلالة إحصائية في متوسط ​​درجات التحصيل في الاختبار في مقارنات جميع المجموعات باستثناء تلك التي تناولت العام الدراسي. بناءً على نتائج الدراسة ، أوصي بتوسيع نطاقها من خلال إجراء دراسات مختلفة تستكشف فهم YCPSTs لمفاهيم الكيمياء الأخرى في إعداد البرامج المختلفة لـ YCPSTs.

Conceptual understanding of acids and bases concepts and motivation to learn chemistry

ABSTRACTThe purpose of this study was to investigate the effect of 5E learning cycle model oriented instruction (LCMI) on 11th-grade students' conceptual understanding of acids and bases concepts and student motivation to learn chemistry. The study, which lasted for 7 weeks, involved two groups: An experimental group (LCMI) and a control group (the traditional teacher-centered instruction [TTCI]). Based on multivariate analysis of covariance results, the LCMI students outperformed the TTCI students in terms of conceptual understanding about acids and bases. Similarly, the students from the experimental group scored higher motivation and this difference was found to be statistically significant. These findings demonstrated that instruction based on learning cycle model provide students a deeper conceptual understanding, foster high-order thinking, engage them in the learning process, and influence their motivation to learn by increasing the relevance of school chemistry to their daily lives.

Development of a three-tier test to assess high school students’ understanding of acids and bases

Two-tier tests are such as assessment tools that can make available for teachers/researchers to determine students alternative conceptions and whether a student gives a correct response to a question by understanding the related subject since the secondtier of a test asks for a reason for the first-tier response. The purpose of this study was to develop a valid and reliable three-tier diagnostic test to assess students’ understanding of acids-bases concepts. For developing this test, interviews and open-ended questions were administered to high school students and related literature was reviewed; the findings obtained from these steps construct the three-tier test.

Thai Grade 11 students’ alternative conceptions for acid–base chemistry

This study involved the development of a two‐tier diagnostic instrument to assess Thai high school students’ understanding of acid–base chemistry. The acid–base diagnostic test (ABDT) comprising 18 items was administered to 55 Grade 11 students in a science and mathematics programme during the second semester of the 2008 academic year. Analysis of students’ responses from this study followed the methodology outlined by Çalik and Ayas. The research findings suggest that the ABDT, the multiple choice diagnostic instrument, enables researchers and teachers to classify students’ understanding at different levels. Most students exhibited alternative conceptions for several concepts: acid–base theory, dissociation of strong acids or bases, and dissociation of weak acids/bases. Interestingly, one of the concepts that students appeared to find most difficult, and for which they exhibited the most alternative conceptions, was acid–base theory. Some alternative conceptions revealed in this study differ from earlier reports, such as the concept of electrolyte and non‐electrolyte solutions as well as the concentration changes of H3O+and OH− in water. These research findings present valuable information for facilitating better understanding of acid–base chemistry by providing insight into the preventable and correctable alternative conceptions exhibited by students.

The effects of guided inquiry instruction incorporating a cooperative learning approach on university students' achievement of acid and bases concepts and attitude toward guided inquiry instruction

The purpose of this study was to investigate the effects of guided inquiry instruction incorporating with cooperative learning environment on University students’ achievement of acid and bases concepts and attitude toward guided inquiry instruction. The subject of this study consisted of 55 first year University students from two intact classes of a Chemistry Course instructed by the same teacher. One of the classes was randomly assigned as the experimental group and the other was assigned as the control group. Researcher prepared worksheets which were related to acid- based concepts based on guided inquiry instruction from the book which is written by (Moog and Farrell, 2006). The experimental group was cooperatively studied worksheets in the groups while the control group was individually studied worksheets in the class. Acid and Bases Achievement Test (ABAT) was administered to the experimental and the control groups as pre and post-tests to measure the students’ understanding of acid and bases concepts and Attitude Toward Guided Inquiry Instruction Scale (ATGIIS) was also used as pre and post-test for both of groups. Multi Variance Analysis (MANOVA) was used to analyze the data. The results showed that students in the experimental group had better understanding of acid and bases concepts and more positive attitude toward guided inquiry instruction. Key words: Guided inquiry, cooperative learning, acid and bases.

Experienced Teachers’ Pedagogical Content Knowledge of Teaching Acid–base Chemistry

We investigated the pedagogical content knowledge (PCK) of nine experienced chemistry teachers. The teachers took part in a teacher training course on students’ difficulties and the use of models in teaching acid–base chemistry, electrochemistry, and redox reactions. Two years after the course, the teachers were interviewed about their PCK of (1) students’ difficulties in understanding acid–base chemistry and (2) models of acids and bases in their teaching practice. In the interviews, the teachers were asked to comment on authentic student responses collected in a previous study that included student interviews about their understanding of acids and bases. Further, the teachers drew story-lines representing their level of satisfaction with their acid–base teaching. The results show that, although all teachers recognised some of the students’ difficulties as confusion between models, only a few chose to emphasise the different models of acids and bases. Most of the teachers thought it was sufficient to distinguish clearly between the phenomenological level and the particle level. The ways the teachers reflected on their teaching, in order to improve it, also differed. Some teachers reflected more on students’ difficulties; others were more concerned about their own performance. Implications for chemistry (teacher) education are discussed.

Acid–base tutorial

The Acid–Base Tutorial is a comprehensive and interactive resource devoted to abolishing the stigma of complexity with which students associate acid–base imbalances. This is a learning site that provides interactive explanations of many aspects of acid–base physiology utilizing chemical, mathematical, and graphical representations. The tutorial homepage offers a colourful, box-structured table of contents made up of 21 main links covering topics such as the physiology of acid–base disorders, the interpretation of blood gases, respiratory and metabolic treatments, and also includes a direct e-mail link to the author. There is a 'Terminology' link that provides detailed definitions and descriptions of 22 common terms, 'Index' and 'References' links, and a 'Plastic Cards' link that provides the option of ordering a pocket 'acid–base card'. Most of the main links open a separate pop-up window containing numerous sublinks through which the user can navigate. Key terms are highlighted throughout the text and are linked to their definition or corresponding sections within the website, with references linked to their full citation. This may cause confusion for some, as it is easy to lose one's navigational path after more than a few links have been opened. The interactive aspects of the site are innovative, and are very helpful. An interactive option called the 'pH Playground' allows the user to manipulate blood gas values, and provides explanation of the corresponding disorder that results. 'Test Yourself' is an interactive multiple choice test for sample blood gases, with automatic assessment and evaluation of the overall acid–base scenario. The Acid–Base Tutorial is an innovative tool that students at all levels can use to build a better understanding of acid–base physiology and the clinical interpretation. The website provides a complete approach to learning with visually appealing graphics, and interactive illustrations of difficult concepts.

Pediatric gastroesophageal reflux disease--current perspectives.

Although heartburn and regurgitation are common manifestations of gastroesophageal reflux disease (GERD), otolaryngologic or respiratory symptoms may be the only indication of GERD. This review focuses on the recent developments in the pathophysiology, diagnosis, and treatment of GERD and their implications in pediatrics. Newer diagnostic modalities include intraesophageal impedance and Bravo wireless pH monitoring. Impedance technology measures both acid and non-acid reflux, whereas the Bravo capsule allows prolonged pH monitoring under more physiologic conditions. In managing children with GERD, there is increasing evidence that they need higher dosages of acid suppressive therapy to achieve clinical response. Alternative therapeutic options are also currently being explored, including pharmacotherapy that targets the primary mechanism for GERD. Endoluminal therapy for GERD in adults as an alternative to surgery has been an exciting development. At present, two of these procedures, Stretta (using radiofrequency energy) and Endocinch (gastroplication), have been approved by the Food and Drug Administration for use in adults. Impedance technology has increased our understanding of acid and nonacid reflux; however, normal values for children are not yet established. There are also limitations to the applicability of the new endoluminal therapies in children. Further research is needed before these developments can be recommended for use in pediatric practice.

Partial characterization of H-translocating inorganic pyrophosphatase from 3 citrus varieties differing in vacuolar pH.

Vacuolar pyrophosphatase (V-PPase) from juice cells of 3 citrus varieties (differing in their vacuolar pH) were partially characterized using purified tonoplast vesicles. Total V-PPase activity was highest in vesicle samples from sweet limes with vacuolar pH of 5.0, while samples from acid limes (with lowest vacuolar pH of 2.0) had the minimal total V-PPase activity. Samples from 'Valencia' orange had intermediate V-PPase levels. When assayed at equal V-PPase activity (measured as Pi production), V-PPase was not able to generate a pH gradient (DeltapH) in vesicles from acid lime, despite its capacity to form a DeltapH in the presence of ATP. Vesicles from sweet lime and 'Valencia' orange were able to form similar DeltapHs in the presence of PPi and ATP supplied together or separately. Antibodies raised against a peptide corresponding to the catalytic site of mung bean V-PPase reacted with samples from all varieties, coinciding with their capacity to hydrolyze PPi. However, antibodies raised against the entire V-PPase polypeptide from mung bean recognized V-PPase from sweet lime and 'Valencia' orange, but did not recognize acid lime samples even at elevated protein concentrations. The structural differences highlighted by antibody recognition, substrate affinity and proton-pumping reactions of V-PPase presented here may reflect evolutionary adaptations related to its reduced function under in vivo conditions and are in agreement with our understanding of acid, sugar accumulation and vacuolar pH changes during the development and maturation of citrus fruits.

Entertaining Chemistry: Part 1. A Volcanic Serpent; Part 2. A Homemade Hydrogen Rocket; [Part 3.] Johnny's Saga in Chemistry

Three tested demonstrations are described here. The first, "A Volcanic Serpent", demonstrates spontaneous delayed combustion and exothermic reactions and is a good analogy for crystal growth. The second, "A Homemade Hydrogen Rocket", describes how a rocket can be made using such simple materials that the experiment can be performed at home, provided that proper precautions are taken. Finally, "Johnny's Saga in Chemistry" uses a humorous poem in conjunction with the performance of reactions relevant to the poem to enhace students' understanding of acids and bases.

Influence of levels of information as presented by different technologies on students' understanding of acid, base, and ph concepts

AbstractWe investigated how different levels of information presented by various technologies affected secondary students' understanding of acid, base, and pH concepts. Secondary students who were selected for the study had just completed their study of acid–base chemistry. No attempt was made to provide further instruction. We analyzed changes in the understanding of individual students by constructing concept maps from the propositions that the students used in interviews conducted before and after a series of acid–base titrations. After the initial interview, students were divided into three groups. Within each group, students individually performed the same set of titrations using different technologies: chemical indicators, pH meters, and microcomputer‐based laboratories (MBL). After the titrations were completed, all students were interviewed again. We found that students using MBL exhibited a larger positive shift in their concept map scores, which indicates a greater differentiation and integration of their knowledge of acids and bases. The chemical indicator students exhibited a more moderate positive shift in their concept map scores, and the pH meter students exhibited a smaller positive shift. We also found that the MBL students constructed more inappropriate links in their concept maps than the chemical indicator or pH meter students. However, we speculate that this increased number of inappropriate links indicates a high level of involvement with the technology. We therefore argue that the level of information offered by the technology affected students' understanding of the chemical concepts.