Simple and Fractional Distillation of Cyclohexane and Toluene Purpose: The purpose of this experiment was to become familiar with the processes of simple and fractional distillation. In this experiment a mixture of two volatile compounds, cyclohexane and toluene, were separated with the process of distillation. Distillation relies on each compound having distinct and separate boiling points. The pure products were analyzed with gas chromatography to determine the success of the distillation. Introduction: Distillation is the process of heating a liquid until it boils, then condensing and collecting the resulting hot vapors.
The purpose of the lab was to determine which reactant was the limiting reactant, and to see how much of the other reactant was used. The true molarity of a compound can be defined as the amount of moles per liter of that substance. The equation of this single displacement chemical reaction done during this lab is 2Al(s) + 3CuCl(aq) → 3Cu (s) + 2AlCl2 (aq). In the reaction, the solid Aluminum replaces the Copper in Copper (II) Chloride to produce solid copper, and Aluminum Chloride. In order to find which reactant is the limiting reactant, an equation based on the molarity of the Copper (II) Chloride may be used, or the products of the reaction may be observed.
CHROMATOGRAPHIC METHODS: After successful extraction of phospholipids from their source analysis can be performed for the detection of specific phospholipids. This section will discuss chromatographic methods used for the analysis of phospholipids. All systems of chromatography consist of a stationary and mobile phase. A monster placed on a stationary phase, i.e., a solid or a liquid, and the mobile phase, a gas or a liquid, is allowed by modifying the system. The components of the sample will be separated on the basis of their ranging physical and chemical properties, imparting different affinities for the two phases.
Energetics Aim: To measure the energy released from the complete combustion of a known mass of alcohol or paraffin wax, to heat water. Hypothesis: The combustion of alcohols is exothermic. In this experiment the energy is released from burning a known mass of alcohol in order to heat a known amount of water. A comparison of various alcohols and paraffin wax (methanol, ethanol, propanol, butanol, octanol and candle) as fuels can be made by calculating the quantity of energy transferred to the water. In this experiment, the amount of energy (heat) involved in a chemical change will be determined.
To perform this experiment, we will utilize emission spectra, titrations, and thermal gravimetric analysis, using knowledge from Experiments 10, 4, Titrations of Na2CO3 and NAHCO3 by HCl (hydrochloric acid) will be performed to determine the concentration of HCl, as well as the number of moles of HCl present within the sample of baking soda. As a result, we will be able to determine the molar concentration of HCl by determining its equivalence point (the point on the graph where the exact amount of rectant needed to perform a reaction has been added) from graphical analysis. Na2CO3(aq.) + HCl(aq.) ==> NaHCO3(aq.)
The change in enthalpy relies on the concentration of the salt solution, because different concentrations will produce different enthalpies. There is an equation to determine how much of this heat energy is lost or gained when a reaction is performed. Q = c m (T1-T2) Where: q is the energy in Joules C is the heat capacity, measured in joules per gram per degree Celsius M is the mass of the solution, measured in grams J is the joules G is the grams of water T is the temperature ΔH=ΔE + PΔV = (q p +w) – w = q p Procedure: 1. Follow instructions 1-9 in Appendix A-1 to initialize the MeasureNet workstation. a.
If the reaction is first order, its graphical representation is seen as ln[A] (natural log of concentration) vs. time, and the slope of its like is also the negative rate constant. Finally, for a second order reaction the graph is shown as 1/[A] (inverse of concentration) vs. time, and the slope of its given line is the positive rate constant. By understanding the rate law and finding the value of the correct rate constant with respect to the order of the reaction, one can determine the half-life of the crystal violet. This is because the crystal violet undergoes a decay reaction with the sodium hydroxide. According to Beer's Law, the absorbance of crystal violet is proportional to its concentration.
b. Calculate the fuel value in kJ/g for each of these compounds. c. FOr each hydrocarbon determine the percentage of hydrogen by mass. d. By comparing your answers for part (b) and (c), propose a relationship between hydrogen content and fuel value in hydrocarbons. a) for a we first need to find a balanced equation for when the hydrocarbons combust to form CO2 and H20.
Let’s call this number X. Then the structural formula of BaCl2 hydrate can be written as BaCl2•XH2O. The reaction of dehydration is |BaCl2•XH2O ( BaCl2 + XH2O |(5) | According to the stoichiometry of the reaction (5) |[pic] |(6) | Where N1 is the number of moles of BaCl2 formed in the reaction (5) and N2 is the number of moles of water lost in the reaction (5). To find out N1 you need to divide the mass of BaCl2 after the reaction by its molar mass. To find out N2 you have to determine the mass of water produced in the reaction.
EXPERIMENT 6 Title Kinetics of Chemical Reaction – Iodination of Cyclohexanone Aim To determine the value of the rate constant, k and order of reaction, a, b and c, and also to suggest a mechanism which agrees with the rate equation that has been obtained. Background Theory The basis of the theory of absorbance is as follows: Io ―――――→ sample ―――――→I if Io = I, no absorbance occur Io > I, the sample absorbs certain amount of light wave Io < I, the sample emits certain amount of light of certain wave length. THE HALOGENATION (IODINATION) OF KETONES (CYCLOHEXANONE) This experiment examined the rate of iodination of cyclohexanone in an aqueous medium. To increase the amount of iodine in the solution, iodine is converted to a more soluble complex ion, I3- by the addition of excess iodide ion: I2 + I- →I3- One of the characteristic reactions of ketones is the substitution of a halogen for one of the hydrogen is adjacent to the ketone group. The net reaction is: This reaction has been studied extensively and occurs for a wide variety of ketones.