Naphthalene Lab Report

Combustion Reaction: A chemical reaction between a fuel and an oxidizing agent that produces heat.

The energy released during combustion reactions goes into the surrounding atmosphere because the energy does not disappear it simply goes into the atmosphere of a surrounding area. For example, during the Cheeto experiment the fire being released is the energy but when the fire is out the rest of that energy is moved onto its surrounding like people and the air. One observation that I made during my experiment was when the mass of Cheeto was too big and when the Cheeto began to burn it released its energy onto the can which heated the water inside and that also created energy because the water releases steam and that goes into the air and the people around it. The fire being released wasn't always as expected because if the Cheeto was too big

Heat: The amount of energy associated with the movement of atoms and molecules in matter.

* Which of the following is true? Energy is created when a fuel is burned

In a combustion reaction, a compound or element reacts with oxygen, releasing a large amount of energy in the form of light and heat.

A more detailed explanation of procedures can be found in the lab packet.1 To summarize, samples of benzoic acid and naphthalene were combusted using the Parr 1341 Calorimeter with a Parr oxygen bomb. A massed benzoic acid pellet was placed onto the center of the combustion pan and 10 cm of nickel alloy fuse wire was massed and then threaded through both electrodes on the head of the bomb so that it lay firmly against the acid pellet. 1mL of distilled water was then placed in the bottom of the bomb in order to ensure that all the water produced by the

The substances used during the experiment have some hazardous drawbacks. Some hazards of working with ethanol are eye and skin irritation and organ toxicity (Ethanol). This compound is combustible. Some hazards of working with sodium hydroxide are severe skin and eye irritation (SODIUM HYDROXIDE). This compound is combustible.

The heat of combustion in kJ was -8.372, (Index 1). The heat of combustion in □(kJ/g) is found by (n∆H°rxn)/(mass of fuel burned) , is -20.93□(kJ/g) (Index 1). The heat of combustion in □(kJ/mol) which is found by (n∆H°rxn)/(number of moles), is -5912.4 □(kJ/mol) (Index 1).

In this experiment, the pKa, dissociation constant, of 2-naphthol was determined by measuring the UV-visible absorption spectra of solution of the acid at different pH values.

He first weighed all the carbon dioxide and water that was produced by burning. Between these experiments, he was able to determine that a substance in air combines with burnable materials, to cause combustion. Antoine then called this substance, “oxygen.” This had a great impact because the conclusion of it all was that Antoine Lavoisier was able to demonstrate that water is able to be composed of a combination of oxygen and hydrogen. He demonstrated the role of oxygen in animal and plant respiration.

The purpose of this experiment is to separate a mixture of salicylic acid and naphthalene using extraction, recrystallization and sublimation techniques. Extraction is the separation of compounds from a mixture based on their relative solubilities in different solvents. Sublimation is the process of separation by which a substance transitions from the solid phase into the gas phase, skipping the liquid phase. Recrystallization involves dissolving a substance in an appropriate solvent then crystallizing it as it cools (impurities remain in solution). The melting points of the substances were determined in order to assess their purity and the percent recovery of pure naphthalene and salicylic acid were calculated. According to the results, the melting point of pure naphthalene was between 86°C -89°C range, whereas for pure salicylic acid was 167°C -170°C. Both determined melting points were higher compared to the literature value of 80.26°C and 158.6°C for pure naphthalene and salicylic acid respectively. Lastly, the percent recovery for pure naphthalene and salicylic acid were 17.7% and 71.2% accordingly.

Heat energy (or just heat) is a form of energy which transfers among particles in a substance (or system) by means of kinetic energy of those particles. Heat energy can be transferred by four different methods such as conduction, radiation, convection, and latent heat transfer. In conduction, the heat spreads through a substance when faster atoms and molecules collide with neighboring slower ones and it transfers some of their kinetic energy to them. A great example of conduction is when you can warm your back muscles with a heating pad. Radiation is the process where heat emanates from an object that

1. The number one source of human exposure to Benzene is from cigarettes smoke, a lesser exposure is through crude oil and gasoline. The routes of human adsorption to benzene are mainly inhaling cigarette smoke, as well as gasoline or crude oil odors. Adsorption of Benzene through the skin is another possible route, but not as prominent as inhalation.

Samples of benzophenone, malonic acid, and biphenyl were each tested with water, methyl alcohol, and hexane. Benzophenone was insoluble in water as it is nonpolar while water is highly polar. Benzophenone was soluble in methyl alcohol, dissolving in 15 seconds, because methyl alcohol is intermediately polar as benzophenone is nonpolar. Methyl alcohol is polar but not as much as water. Thus, the nonpolar benzophenone was soluble in methyl alcohol. Benzophenone was partially soluble in hexane because hexane is nonpolar as is benzophenone. Thus, benzophenone was dissolved in hexane. Malonic acid was soluble in water because both malonic acid and water are polar. It took 25 seconds for malonic acid to dissolve in water. Malonic acid was soluble in methyl alcohol because malonic acid is polar and methyl alcohol is intermediately polar, allowing malonic acid to dissolve in the methanol in 15 seconds. Malonic acid was insoluble in hexane because hexane is nonpolar while malonic acid is polar. Biphenyl was insoluble in water as water is highly polar whilst biphenyl is nonpolar. Biphenyl was partially soluble in methanol which is intermediately polar whilst biphenyl is nonpolar, allowing it to dissolve a little. Biphenyl was soluble in hexane because both biphenyl and hexane are nonpolar molecules. Biphenyl dissolved in hexane in 10 seconds.

Chemical reactions that release energy are called exothermic reactions, these reactions are observed by an increase in temperature of the reaction mixture.