The salt crystal is made of positive and negative ions that hold the it together (eg. NaCl or Na+ and Cl-) by electrostatic ion-ion attractions (the attraction of opposite charges). When a salt dissolves in water, the electrostatic attractions between the ions are broken and each ion forms new electrostatic interactions with the water molecules (see figure 1). Whether this process creates an endothermic or exothermic reaction depends on the balance between the ion-ion forces of the solid salt that must be overcome and the dipole-ion forces that stabilize the dissolved ions in solution. Purpose In this experiment, you will be able to: o Distinguish between the terms: exothermic and endothermic reaction.
Now to find this we would also have to look at the heating curve of the experiment. Also we have to look for when and how the physical change from a solid to a liquid (melting) happens to the Lauric Acid. * A heating curve is when you supply heat to an isolated material over a certain amount of time. To see the heating curve you must graph to noticeable see the rise and stabilization of the heat within the material. Also to further example this lab, Phase Change is when one state of matter changes to another state of matter through either endothermic or exothermic change.
In order for an ice cube to melt, it needs to be kept in a warm place for the ice to change state, after the ice melts, it changes into water. The water can change state into gas by EVAPORATION. If more heat is given to the water, say by warming it in a pan, the water molecules move even faster. Given enough heat, they will move so quickly that they escape from the surface of the water altogether. The water boils, turning into gas known as water vapour.
Distillation of Clove Oil Experiment Aim: The aim of this laboratory experiment is to extract clove oil from clove using distillation technique in order to be familiar with the distillation apparatus and the separation technique using organic solvent, and to determine the yield of the oil and the phenolic compound contained. Introduction: Distillation, according to the Oxford Dictionary, is the action of purifying a liquid by a process of heating and cooling. When heated, some compound would become vapour and it would be collected again when it is cooled in condenser by cold water and turned back into its actual form, while the other compound stayed. So, steam distillation, the method used in this experiment, is the action of separating the liquid mixture of water and organic compound (clove oil) by a process of heating and cooling. This method is used because it has two certain advantages, according to Nerdz-Stormes.
(4 points) q = m × c × Δt Given: q=? m = 34.720g c = 4.18 j/(g x °C) Δt = 41.6°C - 25.2°C = 16.4°C q = (34.720g) (4.18 j/(g x °C) (16.4°C) q = 2380.13j You are trying to figure out the energy change of the water which is the surroundings in the lab. To do that you must take the mass of the metal, which for me was Aluminum, and multiply it by the heat capacity of the water, which was given, then multiply that by the change in temperature, which is the final temperature of the mixture
INTRODUCTION A cooling tower is a heat rejection device, which extracts waste heat from processes to the atmosphere via a water stream. The type of heat rejection in cooling tower is by evaporation of small amount water from the water stream that flow through the packing inside the cooling tower. The waste heat transfer to water stream and evaporate small portion of water in the stream to the air and increase the temperature of the air and its relative humidity, and this is discharged to atmosphere. Cooling towers uses either the process of evaporation of water to remove the heat and cool the fluid to the wet-bulb air temperature, or uses only air to cool down the fluid to the dry-bulb air temperature. When air is used to cool down the water, radiation effect, conduction and convection effect, and also evaporation effect would occur.
This hypothesis was chosen because it’s easier to digest hot water than it cold. Materials and Methods There were multiple materials and methods used for this particular latent lab. For example, the groups used the hot plate to heat up the water to different temperatures. Another material that was used was the thermometer used to check the temperature
Experiment 4: Recrystallization of Pure Phthalic Acid, Benzoic Acid, and Naphthalene Experiment 4: Recrystallization of Pure Phthalic Acid, Benzoic Acid, and Naphthalene Introduction: This experiment involves the technique of recrystallization by utilizing the compounds phthalic acid, benzoic acid, and naphthalene. Recrystallization is an effective method in purifying solid organic compounds. It is useful for a majority of solid organic compounds at room temperature. Selecting the appropriate solvent in the recrystallization process is a crucial step. Organic compounds tend to be more soluble in hot solvents than in cold solvents.
Is There a Change in Temperature when an Alkali Neutralizes an Acid? Aim The aim of the experiment was to find out if there was a change in temperature when we added an alkali (Sodium Hydroxide) to an acid (Hydrochloric Acid) to neutralize it. Hypothesis We hypothesized that there was going be a raise in temperature as we add 1ml of Sodium Hydroxide at a time to the Hydrochloric Acid due to the neutralization of the acid. The neutralization is chemical reaction that causes an exothermic reaction. Sodium Hydroxide + Hydrochloric Acid Sodium Chloride + Water NaOH(aq) + HClaq → NaCl(aq) + H2O(l) Variables Independent The independent variable of the experiment was the amount of sodium hydroxide that we added to the acid.
The first of the two experiments was based in calorimetry. Calorimetry is the science behind measuring the heat change during a chemical reaction or change of state. A major component of calorimetry is the element of specific heat. Every metal has its own unique specific heat. This experiment implemented the use of calorimeters, or devices to measure the equilibrium temperature of water and the metal.