Fuels[edit] Oxy-fuel processes may use a variety of fuel gases, the most common being acetylene. Other gases that may be used are propylene, liquified petroleum gas (LPG), propane, natural gas, hydrogen, and MAPP gas. Many brands use different kinds of gases in their mixes. Note: there is not a single gas called "oxyacetylene". Acetylene[edit] Acetylene generator as used in Bali by a reaction of calcium carbide with water.
57 (1) (iii) A triglyceride is also formed in the reaction between glycerol and three molecules of oleic acid, C17H33COOH. State and explain which of the two triglycerides (the one formed from stearic acid or the one formed from oleic acid) has the higher melting point. (the one from) stearic acid; saturated / no (C to C) double bonds; chains pack close together / stronger intermolecular forces / van der Waals’ forces etc; 3 Ignore hydrogen bonding. If wrong choice made, only third mark can be scored. (3) (b) An oil sample containing 0.0100 mol of oil was found to react with 7.61 g of iodine, I2.
By using this method of distillation a mixture is heated to a temperature at which several fractions of the compound is evaporated the distillate is then condensed and collected. Generally the component parts have boiling points that differ by as little as 20-30°C under a pressure of one atmosphere. However, cyclohexene and cyclohexanol have boiling points of 83°C and 161°C, respectively, and fractional distillation was used to separate the starting material from the desired product. The mixture is heated and boiled and the vapors produced are condensed and the distillate is collected and then tested by GC analysis. The Agilent 7890A Gas Chromatography System separates chemicals based on the ease with which they evaporate into a gas, also known as the volatility.
Also, the more stable the free radical that is left behind, the weaker its C-H bond strength will be. The difference between the bromine and chlorine product ratios can be partially explained by the Hammond postulate, which states that species with similar energy levels also have more similar structures and react more quickly and less selectively. In the experiment, five different hydrocarbons were tested to measure the rate of reaction with the addition of bromine. Two trials were done, one with the test tubes containing the hydrocarbons and added bromine sitting directly under a lamp, and another with the test tubes in a closed, dark space. Both trials contained a
Discussion and Conclusion In this experiment, the bromination of an alkene will be observed and a mechanism to account for the occurrence distribution of the products will be determined. In the first part of the experiment the 0.9 grams of E-stilbene will be put in a flask with 10ml of dichloromethane and then stirred to affect dissolution of the E-stilbene, since dichloromethane is a nonpolar solvent which can dissolve the nonpolar alkene. After the E-stilbene has been dissolved, 5ml of bromine in dichloromethane will be added, which will be stirred for thirty minutes until the solution is white, to ensure that the reaction has gone to completion. Bromine in dichloromethane is used because dichloromethane works as a good solvent for bromination reactions, due to the fact that it doesn’t react with bromine or most other organic molecules. The reddish color of bromine is discharged upon addition to an alkene as the bromine reacts, making this reaction a useful qualitative test for unsaturation when the reaction has gone to completion.
No details of how the oxides of nitrogen are formed are required, other than the fact that they are formed at high temperatures. Solid particles may contain soot (carbon) and unburnt fuels. b) The combustion of hydrocarbon fuels releases energy. During combustion the carbon and hydrogen in the fuels are oxidised. 18 GCSE Chemistry for teaching from September 2011 onwards (version 1.0) Additional
ABSTRACT Isopropyltoluene isomers were synthesized through the friedel-crafts alkylation of toluene with 2-chloropropane in the presence of aluminum chloride as a catalyst. Through extraction of the distillate with water and 5% NaHCO3, followed by a fractional vacuum distillation, the desired aromatic organic compound was isolated. Infrared Spectroscopy and Gas Chromatography were used to analyze the composition, purity and to confirm the identity of the prepared product. The sample weighed approximately 2.66g, which reflected a low yield at 47%. However, from the GC the area % (also known as percent purity) was 91.8%, which indicates that a very pure product was obtained.
Recrystallise the crude ester from methanol using a quantity of hot solvent approximately twice the minimum required for complete solution (This is to ensure that the phenyl benzoate does not separate until the temperature of the solution has fallen below the melting point of the ester). Phenyl benzoate separates as colourless crystals. 5. Determine the melting point of the product. Results : Yield (mass in gram) = __________________0.128 g_____________________ Melting point of pure phenyl benzoate (OC) = ___________70O______________ Melting point of your phenyl benzoate (OC) = ___________69O______________ Questions : 1.
These are compounds that are referred to as unsaturated molecules. Finally, a class of cyclic hydrocarbons that contain a closed loop (sextet) of electrons are called aromatic. With so many compounds possible, identification of the bond type is an important step in establishing the molecular structure. Quick, simple tests on small samples can establish the physical and chemical properties of the compounds by class. Some of the observed physical properties of hydrocarbons result from the nonpolar character of the compounds.
Ethanol boils at 78.4 °C while water boils at 100 °C. So, by heating the mixture, the most volatile component will concentrate to a greater degree in the vapor leaving the liquid. Some mixtures form azeotropes, where the mixture boils at a lower temperature than either component. In this example, a mixture of 96% ethanol and 4% water boils at 78.2 °C, being more volatile than pure ethanol. For this reason, ethanol cannot be completely purified by direct fractional distillation of ethanol-water mixtures.