Electrical Determination of the Heat Capacity of a Calorimeter in Approximately One Minute

Abstract

In most general chemistry laboratories, the heat capacity of a calorimeter is determined by measuring the temperature changes that occur when a known mass of water at a higher temperature is added to a known mass of water (or solution) in the calorimeter at room temperature. Another approach is to add a known quantity of electrical energy and measure the temperature change.

Continuous addition kinetic elucidation: catalyst and reactant order, rate constant, and poisoning from a single experiment

“…29 The obtained reactant order was similar to a literature value of 1.01. 25 Likewise, the catalyst order showed good agreement with literature results of 1.03 (ref. 25 ) and 0.94.…”

“…25 Likewise, the catalyst order showed good agreement with literature results of 1.03 (ref. 25 ) and 0.94. 26 These experiments, like CAKE, yielded non-integer reaction orders.…”

“…The overall rate equation is rst order in both reactant and catalyst, due to a combination of H 2 O 2 and I − being involved in the rate-limiting step, and has a reported rate constant of ∼0.01 M −1 s −1 . [24][25][26] Furthermore, the overall rate equation being rst order in both reactant and catalyst is the most common case for catalytic reactions, making the reaction highly desirable for initial testing. Undergraduate laboratory experiments typically use ve experiments to establish order in catalyst and substrate, 25 but CAKE efficiently establishes these values in a single run.…”

“…[24][25][26] Furthermore, the overall rate equation being rst order in both reactant and catalyst is the most common case for catalytic reactions, making the reaction highly desirable for initial testing. Undergraduate laboratory experiments typically use ve experiments to establish order in catalyst and substrate, 25 but CAKE efficiently establishes these values in a single run. Here, O 2 formation led to displacement of a liquid, which was measured using a mass balance.…”

The H3PO4 Acid Ionization Reactions: A Capstone Multiconcept Thermodynamics General Chemistry Laboratory Exercise

“…With high linearity in the slope of the electrical heating thermogram ( R 2 > 0.99), 10–20 s provide 10– 20 data points, which suffice to establish the slope with sufficient certainty. The literature values for the enthalpies of ionization of H 3 PO 4 (aq) are −7.5, 3.3, and 15 kJ/mol for the first, second, and third acid ionizations, respectively. − The results reported by students are within 10% of the literature values suggesting that the entire procedure, including the determination of the calorimeter constant from the heating slope, yield satisfactory results.…”