Introduction: Distillation is the process of heating a liquid until it boils, then condensing and collecting the resulting hot vapors. Chemists have been applying the principles of distillation for thousands of years. Today, distillation is an extremely valuable tool in the modern organic chemistry laboratory, both for the identification and the purification of organic compounds. The boiling point of a compound is one of the physical properties used to identify it. Distillation is used to purify a compound by separating it from a non-volatile or less-volatile material.
The relationship does not apply if a phase change is encountered, because heat added or removed during a phase change does not change the temperature. The graph below demonstrates the structural diagrams of the fuels used. They are arranged in ascending order of heat released upon complete combustion: Fuels Structural Diagram Description Methanol 1 carbon atom 4 hydrogen atoms Ethanol 2
Distinguish between an element and a compound with 2 examples for each An element is a substance that cannot be broken down into any simpler substances. Some examples of Elements are Hydrogen and Helium. A Compound is when two or more elements combine. Examples of this are Water (H2O) and Salt (NaCl) Explain the relationship between the group number and the number of electrons in the valence shell The relationship between the group number and the numebr of
The R tube will then be put in a large beaker. Another large test tube, boiling tube will be needed, along with a Pasteur pipet. A regular sized test tube will be labeled “C” for “colored solution,” and the new boiling tube will be labeled “P” for “product”. One boiling chip will then be placed into the P tube. 5mL of acidified water will be measured, using a graduated cylinder, and will be transferred to the R tube, and will be immediately vigrously mixed with the reactants.
Volume of gas = molar volume x number of moles The molecular formula of gaseous hydrocarbons (CxHy) and organic compounds (CxHyOz) can be determined by combustion in excess oxygen to form carbon dioxide and water, using the following equations: CxHy + (x+ y/4) O2 x CO2 + y/2 H2O CxHyOz + (x+ y/4- z/2) O2 x CO2 + y/2 H2O Example 4 When 10 cm3 of a gaseous hydrocarbon was combusted in excess oxygen in an enclosed vessel, the volume of gas (measured at 298K) was reduced by 25 cm3. The addition of excess NaOH (aq) caused a further reduction in gas volume of 40 cm3 (measured at 298 K). The pressure in the vessel was maintained constant at 1 atm throughout the measurements. Find the molecular formula of the
A) double; covalent B) double; ionic C) single; covalent D) single; ionic E) triple; covalent 3. Which property could describe a covalent compound? A) It conducts electricity when melted. B) Has a low boiling point C) It is composed of a non-metal and a metal. D) It conducts electricity when dissolved in water.
Another means of classification depends on the type of bonding that exists between carbons. Hydrocarbons which contain only carbon-to-carbon single bonds are called alkanes. These are also referred to as saturated molecules. Hydrocarbons containing at least one carbon-to-carbon double bond are called alkenes, and those compounds with at least one carbon-to-carbon triple bond are called alkynes. These are compounds that are referred to as unsaturated molecules.
LabQuest 34 Vapor Pressure and Heat of Vaporization Vapor pressure or scientifically called equilibrium vapor pressure is the condition wherein the vapor from a liquid over the same liquid in a sealed container is at a point wherein the amount of gas leaving the liquid equals the amount of gas re-entering the liquid from the vapor above the liquid. However there is a mathematical between temperature and vapor pressure, and the Clausius-Clayperon equation attest to this relationship. Clausius-Clayperon equation - ln P = - [∆Hvap / R][1/T] +C The intent of this experiment was to determine the temperature/vapor pressure relationship using the volatile liquid ethanol, CH3CH2OH; and calculate its heat of vaporization. This data was collected over a range of temperatures, 22.4° C to 34.9° C. It was intentional that the temperature remained under 40° C less the pressure inside the Erlenmeyer flask got high enough to pop the stopper out of the Erlenmeyer flask. Materials and equipment: MATERIALS Labquest 20 mL syringe Labquest App two 125 mL Erlenmeyer flasks Vernier Gas Pressure Sensor ethanol, CH3CH2OH Temperature Probe 400 mL beaker rubber stopper assembly 1 liter beaker plastic tubing with two connectors hot plate Procedure: The apparatus was set up as requested by the Lab quest 34 handout and an initial pressure reading of 101.6kpa was obtained at room temperature, 22.4° C. Then the Erlenmeyer flask and the sensors were conditioned to the water bath by holding the flask down into the water bath to the bottom of the white stopper for 30 seconds, and then the valve on the white stopper was closed to keep the ethanol vapor from leaving the container at any time during the experiment.
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.
As long as the electronegativity difference is no greater than 1.7, the atoms can only share the bonding electrons. An example of a covalent bond would be water, its two hydrogen atoms with one oxygen atom (H2O). If two atoms differ considerably in their electronegativity than one of the atoms will lose its electron to the other atom. This results in a positively charged ion (cation) and negatively charged ion (anion). The bond between these two ions is called an ionic bond.If the electronegativity difference is greater than 1.7 then the higher electronegative atom has an electron attracting ability which is large enough to force the transfer of electrons from the lesser electronegative atom.