Nurtaç Canpolat

REMOVAL OF PHOSPHATE FROM WASTEWATERS

Abstract Gas concrete waste was used to remove phosphate from aqueous solutions in this study. The influence of suspension pH, temperature, mixing rate, and gas concrete dosage on phosphate removal was investigated by conducting a series of batch adsorption experiments. In addition, the yield and mechanisms of phosphate removal were explained on the basis of the results of X-ray spectroscopy, measurements of zeta potential of particles, both values of BET–N 2 specific surface area, and images of scanning electron microscopy (SEM) of the particles before and after adsorption. In this study, phosphate removal in excess of 99% was obtained and it was concluded that wastes of gas concrete are an efficient adsorbent for the removal of phosphate. The removal of phosphate predominantly takes place by precipitation mechanism and the weak physical interactions between the surface of adsorbent and the metallic salts of phosphate.

The conceptual change approach to teaching chemical equilibrium

This study investigates the effect of a conceptual change approach over traditional instruction on students’ understanding of chemical equilibrium concepts (e.g. dynamic nature of equilibrium, definition of equilibrium constant, heterogeneous equilibrium, qualitative interpreting of equilibrium constant, changing the reaction conditions). This study consisted of 85 undergraduate students from two classes enrolled on an introductory chemistry course. One of the classes was assigned randomly to the control group, and the other class was assigned randomly to the experimental group. During teaching of the topic of chemical equilibrium concepts in the chemistry curriculum, the conceptual change approach was applied in the experimental group whereas ‘traditional instruction’ was followed in the control group. The data were analyzed using analysis of covariance. The results showed that the students in the experimental group performed better compared to the control group. The average percent of correct responses of the experimental group was 70%, and that of the control group was 51%, after treatment. In addition, it was found that students’ science process skills made a statistically significant contribution to the variation in students’ understanding of chemical equilibrium concepts.

Prospective chemistry teachers' misconceptions about colligative properties: Boiling point elevation and freezing point depression

This study aimed at identifying prospective chemistry teachers’ misconceptions of colligative properties. In order to fulfill this aim, a diagnostic test composed of four open-ended questions was used. The test was administered to seventy-eight prospective chemistry teachers just before qualifying to teaching in secondary schools. Nine different misconceptions were identified and qualitatively discussed. The results have implications for teaching colligative properties and in general tertiary level teaching, suggesting that a substantial review of teaching strategies is needed.

Development And Application Of Two-Tier Multiple Choice Instrument On Some Concepts Of Chemistry

The aim of this study is to develop a two-tier multiple-choice instrument about evaporation, evaporation rate and vapor pressure and to investigate its applicability. Firstly, with this aim, in the light of literaure students’ misconceptions were determined relating to these concepts. Later, based on the misconceptions idendified the two-tier multiple-choice diagnostic instrument consisting of 16 items was developed. The test was conducted to a sample of 208 students engaged in chemistry teacher program, matter analysis of the test items was carried out and the misconceptions held by the students were discussed by evaluating their responses to the items.

SINIF ÖĞRETMENLİĞİ ÖĞRENCİLERİNİN MUMUN YANMASIYLA İLGİLİ ANLAYIŞLARI

Bu calisma, sinif ogretmeligi ogrencilerinin mumun yanmasi ile ilgili anlayislarini ortaya koymayi amaclamaktadir. Bu amacla, bes acik uclu sorudan olusan bir test gelistirilmistir. Bu test, Ataturk Universitesi, Kazim Karabekir Egitim Fakultesi, Sinif Ogretmenligi Bolumunun ucuncu sinifinda okumakta olan toplam 72 ogrenciye uygulanmistir. Ayrica 15 ogrenciyle de yari yapilandirilmis mulakat yapilmistir. Verilerin analizinde, ogrencilerin kavram yanilgilarini ortaya koyabilmek amaciyla icerik analizi yontemi kullanilmistir. Sonuclar, ogrencilerin mumun yanmasiyla ilgili olarak bazi yanlis kavramalara sahip oldugunu ortaya koymustur.