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Two carbons of different origins (wood and coal) were oxidized with nitric acid. The materials were characterized using sorption of nitrogen, Boehm titration, and potentiometric titration. The water adsorption isotherms were measured at various temperatures close to ambient (relative pressure from 0.001 to 0.3). From these isotherms heats of adsorption were calculated using virial equation. The results showed that the isosteric heats of water adsorption are affected by surface chemical heterogeneity only at low surface coverage. The shapes of heats obtained indicate strong water−water interactions as a result of adsorption on secondary sites and cluster formation. In all cases the limiting heat of adsorption equal to the heat of water condensation (45 kJ/mol) was obtained.

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The surface features of two carbons of wood origin were compared. One sample was manufactured using phosphoric acid activation and the other using potassium hydroxide activation. To check the susceptibility to oxidation and the stability of the porous structure, the samples were oxidized with ammonium persulfate. Structural properties of carbons and their oxidized counterparts were determined using sorption of nitrogen. Surface acidity was evaluated using Boehm titration, potentiometric titration, inverse gas chromatography, and diffuse reflectance FTIR. It was demonstrated that, despite the same wood origin, the carbons significantly differ in their pore structure and surface chemistry. The carbon obtained using KOH activation is homogeneously microporous with high surface area around 2300 m2/g (BET). On the other hand, the carbon manufactured using phosphoric acid contains a high volume of mesopores and its surface area is significantly lower. The carbons also differ in their surface chemistry and susceptibility to oxidation.

A sample of Westvaco carbon was oxidized with ammonium persulfate and both initial and oxidized samples were washed with methanol. The samples were characterized using sorption of nitrogen, Boehm titration, potentiometric titration, IGC, FTIR, TPD, and thermal analysis. Then water adsorption isotherms were measured at various temperatures close to ambient (relative pressure from 0.001 to 0.3). The isotherms were analyzed in terms of the thermodynamic consistency, presence of equilibrium, and water-activated carbon surface interactions. The results showed that washing with methanol significantly modifies the surface chemistry of carbons, creating phenols and new, very easily hydrolyzed esters. The latter, when in contact with water, is hydrolyzed, creating carboxylic acids and methanol. This may result in unjustified application of the Clausius−Clapeyron equation to calculate the isosteric heat of adsorption.

Chemistry is considered difficult to students to learn because many of its concepts are abstract in nature and require visualization at the sub-microscopic level of representation. Physics Education Technology (PhET) offers students the ability to understand and relate both chemical systems and what is happening at the sub-microscopic level through dynamic visualization. Simulations like PhET can be used as a powerful transformative tool for the teaching and learning of science. The research design and paradigm goal is to investigate the students' perceptions on the impact of PhET simulations on their learning and attitudes and to identify PhET's most helpful features. The data gathering tool in this research project is a survey that comprised of Likert-type and open-ended questions that was handed out to students who have completed General Chemistry II and were acquainted with PhET simulations as part of their laboratory sessions. The research took place at the City College of New York, an urban, minority serving, and public college. The number of research participants is 158. The implications of the research findings are PhET interactive simulations have an overall positive impact on students' attitudes and perceptions about learning, PhET simulations promote students' development of conceptual understanding of chemistry concepts and content, PhET simulations seem to promote and facilitate learning and understanding of abstract concepts, and PhET simulations furnish learning opportunities that otherwise cannot be attained in a traditional laboratory setting. The data presented in this paper support the notion that there is a need to update and modify general chemistry laboratories to reflect emerging technologies such as PhET interactive simulations.

Organic chemistry is often regarded as a difficult subject which deters learners and is associated with poor performance. Our research aims to examine some of the challenges that students face in learning organic chemistry topics related to acid/base and resonance structures theories. For this purpose, organic chemistry exams were analyzed in regards to these troublesome topics. A questionnaire was administered to further understand some of the challenges students face when enrolled in organic chemistry. Our data show that students face several challenges learning these topics and that there is a need to change the way these topics are addressed in instruction.