1.What is thermochemistry and how is it useful? How can thermochemistry be applied in the real world? Thermochemistry is the branch of thermodynamics that focuses on th heat involved in a chemical and physical change. A reaction may release or absorb energy. It is useful at predicting reactant and product quantities through a reaction.
Measuring acid reactions Introduction: This experiment review will show how different each acid reaction is different from each other. There were two different experiments; one measures the temperature of the reaction and the other measures the pH level. The reaction can be endothermic or exothermic. The differences between them are simple; exothermic puts out energy which makes it warm to touch. As for endothermic the reactions pulls in energy and makes it cold to touch.
Required Materials: Solids: KNO3 unknown concentration, KNO3 Liquids: Tap Water, DI Water Other: 1 burette, 1 1000 mL beaker, 5 test tubes, thermometer, heating pad Objectives: • To determine the effect of temperature of the solubility of a salt. • To construct a solubility curve for the salt. • To determine the mass of an unknown size sample of the salt. Theory: Solubility is a measure of t he amount of one substance that can be dissolved in a measured amount of another substance. In this experiment we are going to measure the solubility of KNO3 in water at various temperatures.
Specific Heat Lab BACKGROUND Calorimetry is used to determine the heat absorbed or released during a chemical reaction. . Specific heat is the amount of energy, measured in joules, needed to raise the temperature of one gram of the substance one Celsius degree. An important tool needed to figure out specific heat is a calorimeter. The calorimeter was designed in 1780 by a chemist named Antoine Lavoisier with help from a mathematician by the name of Pierre Simon de Laplace.
In this experiment, the freezing point for the solvent biphenyl will be determined theoretically and experimentally, as well as the verification of the freezing point depression equation for a solvent/solute mixture. Represented by the equation kf=RTf2MΔHf , the freezing point depression will be constant for a solvent despite whether a solute is involved in the experiment. The freezing point equation can later be used to calculate the temperature the solvent freezes represented by the equation, ΔTf=-ikfnsolutemsolvent . The freezing point of the solvent containing a nonvolatile electrolyte will be equal to the addition of the freezing point depression to temperature of the pure solvent and will always be lower than the freezing point of the pure solution. Because the freezing point depression is a colligative property, the higher the concentration of
According to the Le Chatelier’s principle, if a chemical system at equilibrium experiences a change in concentration, temperature, volume, or partial pressure, then the equilibrium shifts to counteract the imposed change and a new equilibrium is established. In this experiment, the effect of temperature change on the equilibrium position of the above chemical equation by comparing the state of the reacting mixture when it is in high temperature and low temperature. As the ∆H>0, the increase of temperature would expected to shift the equilibrium to the right. Procedure: 1. Using a measuring cylinder, pour 20 cm3 of 0.01M saturated cobalt (II) chloride solution at 0℃ and pour about 100 cm3 of deionized water to a 250 cm3 beaker.
CRUDE OIL DISTILLATION Introduction In this experiment, we conducted a distillation experiment of crude oil. We were able to see how the chemical properties of the components of crude oil influence the temperature it distills out of the crude oil. Distillation is used to remove impurities like distilled water or to separate liquids. It separates substances based on their boiling point. In this case, a sample of crude oil is heated.
Since boiling point and vapor pressure are inversely proportional, the separation is thus based on the vapor pressure as well. In order for the distillation to be effective, the components of the solution must have significantly different boiling points, preferably between 30-40℃. In this experiment, hexane has a boiling point of 69℃, while toluene has a boiling point of 111℃. A liquid is heated to its boiling point and the vapors generated are condensed by cooling and collected in a receiving vessel. One vaporization and condensation cycle is called a theoretical plate.
AIM/ OBJECTIVE In this experiment, bomb calorimetry will be used to determine the heat of combustion (heat that the fuel gives off over a certain amount of time when it’s ignited). Determine the Calorific Value of the fuel used and show how the practically determined value compares to the theoretical calculations and industry standards 2. THEORY A bomb calorimeter is a sealed container capable of holding several atmospheres of gas pressure. It measures the enthalpy of reaction by carrying out the combustion reaction under constant volume conditions. This exothermic reaction increases the temperature inside the bomb, which then transfers the energy to the external water jacket raising the external temperature.
Experiment 15: Molar Mass Determination by Freezing Point Depression Introduction The purpose of this experiment is to determine the molar mass of camphor by determining the freezing point depression of cyclohexane. In this experiment a sample of the solvent cyclohexane was cooled to its freezing point and a cooling curve was constructed. A known mass of camphor was added to the known mass of camphor and the freezing point of the solution was determined using equations 1 and 2. From the freezing point depression the molality of the camphor can be calculated and then the molar mass, by using equation 3. If Tf(solvent) is defined as the freezing point of the pure solvent, and if Tf(solution) is defined as the freezing point of the solution, then the freezing point depression (in °C) is given by equation 1: ΔTf = Tf(solvent) - Tf(solution) (1) The freezing point depression ΔTf is related to m, the molality of the solution particles, given in equation 2: ΔTf = Kf m (2) If a known mass of a solute is placed into a known mass of solvent, and the freezing point depression relative to the pure solvent determined, then the molar mass (MM) of the solute can be determined by using the appropriate Kf value for the solvent, equation 3: ΔTf = Kf (mol/kg solvent) = Kf (g solute/MM solute) / kg solvent (3) Procedure Determination of the Freezing Point of Cyclohexane A 20 x 50 mm test tube was rinsed clean with cyclohexane.