Introduction Heat is the form of energy, thermal energy, which flows between two substances due to their difference in temperature.1 The measurement of heat flow is called Calorimetry and the apparatus used to measure the heat flow (temperature change) for a reacting system is called a calorimeter. The calorimeter is well-insulated device that help to minimize the heat exchange between the system being observed and its surroundings. In this experiment, simple calorimeter, coffer cup calorimeter containing Styrofoam cups is used. Calorimeter contains a thermometer and a stirrer.3 Thermometer is typically inserted in the calorimeter to measure the change in the temperature that results from the reaction. Stirrer is used to keep the contents
There will be a stir that helps distribute the heat evenly all through the water. A temperature probe determines the amount of heat given off and converts it to joules. Components of a Bomb Calorimeter The main elements of a bomb calorimeter are: • Dewar or insulating jacket: is the body of the calorimeter which is made up of a doublewalled flask of metal with a vacuum between the two walls to prevent the transfer of heat.
EXPERIMENT Polyol process is used for the synthesis of the nanoparticles. A polyol is an alcohol containing multiple hydroxyl groups. This process involves hydrolysis and inorganic polymerization carried out on the salts dissolved in a polyol medium. The polyol acts as a solvent for the precursor salts because of its high relative permittivity, and allows one to carry out hydrolysis reactions under atmospheric pressure in a large temperature range up to the boiling point of the polyol. Ethylene glycol has been widely used in the polyol process for the synthesis of metal (pure and alloyed) nanoparticles due to its strong reducing power and relatively high boiling point (~1970C).
10, is a linear curve for 4-NP reduction using AuNPs. It was observed that the increase in temperature helps the rate of reaction to increase. The activation energy was calculated from the slope of the straight line and was found to be 7.4 ± 1.34 k Cal/mol. The above results are of clear indication that catalysis usually takes place on the surface of the nanoparticles. 3.8 Catalytic reduction of potassium hexacyanoferrate (III) The electron transfer reaction between hexacyanoferrate (III) and sodium borohydride results in the formation of hexacyanoferrate (II) ion and dihydrogen borate ion and this reaction is strongly catalyzed by AuNPs.
I. Introduction This experiment uses calorimetry to measure the specific heat of a metal. Calorimetry is used to observe and measure heat flow between two substances. The heat flow is measured as it travels from a higher temperature to a lower one. Specific heat is an amount of heat required to raise the temperature of one gram of anything one degree Celsius.
It is presented as qsoln-q cal. Calorimeter heat change is equal to temperature change multiplied by the calorimeter heat capacity (Ccal). Experiments two and three both have negative heat neutralization for part 2 (NaOH and HCL) and (Mg and HCl), thus the temperature increases as the reaction moves from initial to final
4) Polysulfone (PSU) The foaming behavior of PSU foams is very similar to that of COC discussed above. PSU is potentially useful for high temperature applications. Cell nucleation density as high as 1015 cells/cm3 can be achieved with PSU foams. Thus cell sizes in the nanocellular range (20-30 nm) can be achieved. Foaming is carried out by the solid state foaming process.
The goal of the experiment is to synthesize a bromohexane compound from 1-hexene and HBr(aq) under reflux conditions and use the silver nitrate and sodium iodide tests to determine if the product is a primary or secondary hydrocarbon. The heterogeneous reaction mixture contains 1-hexene, 48% HBr(aq), and tetrabutylammonium bromide and was heated to under reflux conditions. Heating under reflux means that the reaction mixture is heated at its boiling point so that the reaction can proceed at a faster rate. The attached reflux condenser allows volatile substances to return to the reaction flask so that no material is lost. Since alkenes are immiscible with concentrated HBr, tetrabutylammonium bromide is used as a phase-transfer catalyst.
Testing the Strength of the Electromagnet by Changing the Number of Coils Aim The aim of this experiment is to investigate how the strength of an electromagnet is affected by the number of coil turns around the iron c-core. Hypothesis As the number of wire coils increases, the strength of the magnetic field (the electromagnet’s strength) will also increase. This means that the number of paper clips that attach to the electromagnet will increase. Explanation of Hypothesis/background: When a DC (Direct Current) electric current flows through a wire, a magnetic field is created. Wrapping the wire in a coil concentrates and increases the magnetic field, because the additive effect of each turn of the wire.
The table below shows how the additives affect the mechanical properties. The number of additives are numerous and show the versatility of Poly (ether sulphone) to incorporate new materials in making composites. The different additives are added as per requirement of application. For example, addition of Graphene oxide to improve the thermal and mechanical properties. The mechanical properties effect is shown through the comparison of Poly (ether sulphone) with 30% Carbon fibre and with 40% Glass fibre.