Cooling process: By cooling down the material through some chemical reactions in which energy absorbing (endothermic) processes triggered by additives and/or the chemical release of water cool the substrate to a temperature below that required for sustaining the combustion process, e.g. magnesium hydroxide [26,13,20]. Coating process: By forming a protective layer or coating that prevents or shields the underlying combustible layer of material with a solid or gaseous protective layer from heat and oxygen necessary for the combustion process, e.g. phosphorous and boron compounds [26,13,20]. Dilution process: By incorporating inert substances (e.g.
Thus the absorber consists of the weak solution of the refrigerant (ammonia in this case) and absorbent (water in this case). When ammonia from the evaporator enters the absorber, it is absorbed by the absorbent due to which the pressure inside the absorber reduces further leading to more flow of the refrigerant from the evaporator to the absorber and solution becomes strong. This strong solution is pumped to generator using circulating pump. At high temperature water absorbs lesser ammonia, hence it is cooled by the external coolant to increase it ammonia absorption capacity.The refrigerant leaving the evaporator enter the absorber, where it is absorbed by the absorbent. The refrigerant then enters the condenser while the remaining weak solution enters back to the absorber and the cycle is repeated.
Samples separates into the stationary liquid phase, based on their solubilities at the given temperature. The components of the sample called solutes or analytes separate from one another based on their relative vapour. This chromatographic process is called elution.
Chemical reactions transform bond energy into heat or work. Enthalpy of reaction (Hrxn) is the term used for the change in heat as a reaction is carried out at constant pressure. It is a state function as it only depends on the final and initial conditions during the change of state. If Hrxn < 0, the system releases heat and is therefore an exothermic reaction. On the other hand, if Hrxn > 0, the system absorbs heat.
Air conditioning means, the air conditioning for the maintenance of the specific conditions of temperature, humidity (moisture in the air) and the level of dust inside a closed space. The conditions that remain are dictated by the need for the conditioned space is intended. The air conditioning system removes heat leaking into the structure from the outside and deposits it outside the structure where it came from. A basic air conditioning system consists of three main components: • Compressor: compresses the low pressure refrigerant (low temperature) to high pressure (high temperature). This conversion increases the boiling point to higher temperature levels, which facilitates the removal of heat brought by the outside air.
The ester studied was “3,” the acid used was 9.5 mL of “B,” and the alcohol used was 18.1 mL of “C.” A few substances were added to augment the production of the ester. Sulfuric acid (H2SO4) was added using a dropper bottle to catalyze the reaction. The desiccant in this reaction was drierite and was used to absorb the water byproduct. This prevented the ester from breaking apart into its constituents. The cold finger condenser was used to trap evaporated gas from the heated mixture, and condense it back into
Catalase reacts with hydrogen peroxide, binding onto it and breaking it down into the less toxic water and oxygen. The equation for this reaction is the following: 2 H2O2 = 2 H20 + 2 O2 This experiment will use 1% catalase solution and 3% hydrogen peroxide solution, both diluted into water so the reaction slows down. Temperature will be controlled in this experiment to change the reaction speed of the enzyme and the substrate, this is what the experiment is looking at. The effect of the temperature will be determined by how much gas is released in two minutes, which will change the pressure inside the test tube and will be measured by a gas
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
Thermal gelatin property is a solution when heats up to a critical temperature, it congeals into a non-flowable but semi-flexible mass. Whereas this critical (congealing) temperature is inversely related to both the solution concentration of HPMC and the concentration of the methoxy group within the HPMC molecule ( higher the concentration of the methoxy group, the lower the critical temperature. The inflexibility/viscosity of the resulting mass, is directly related to the concentration of the methoxy group (so higher the concentration, the more viscous or less flexible the resulting mass is). USES The application for HPMC are as follows:- Tile adhesives Cement
However, in case of separation of solid impurities from liquid or liquids with high difference in boiling points Simple distillation can be preferred. Introduction Distillation is a specific technique of separating mixtures based on differences in propensity to vaporize of components in a boiling liquid mixture (Palleros, 2000). Distillation is a physical separation process, which does not involve chemical reaction and used for purification of liquids which do not undergo decomposition at their boiling point. There are several types of distillation including simple distillation, fractional distillation, vacuum distillation and steam distillation (ibid.). The type of used distillation depends on the nature of the liquid and the nature of impurities present in it.