The way reactants concentration affects the reaction rate is commonly known as the rate law. "The rate law can only be experimentally determined and can be used to predict the relationship between the rate of a reaction and the concentrations of reactants,"(Holt 2006). To understand or determine the rate of this chemical process one can make an educated guess about the reaction mechanism. "The reaction mechanism is the way in which a chemical reaction takes place, expressed in a series of chemical equations. A reaction that involves a single reactant, the rate is often proportional to the concentration of the reactant raised to some power” (Holt 2006).
Question: What is the solubility curve of KNO3 Prediction: Draw a sketch to show the shape of the curve you expect for the solubility of a typical solid dissolving in water at different temperatures. Plot solubility on the y-axis and temperature on the x-axis. Materials: Large test tube Balance Stirring wire Two-hole stopper to fit the test tube, with a thermometer inserted into one hole 400mL beaker graduated cylinder or pipette or burette hot plate or Bunsen burner with ring clamps and wire gauze retort stand and thermometer clamp potassium nitrate, KNO3 distilled water Procedure: 1. Read through the steps in this procedure. Prepare a data table to record the mass of the solute, the initial volume of water, the total volume of water after step 9, and the temperatures at which the solutions began to crystallize.
Introduction Generally, two important questions may be asked about a chemical reaction: (1)How far do the reactants interact to yield products, and (2) how fast is the reaction? “How far?” is a question of chemical equilibrium which is the realm of chemical thermodynamics. “How fast?” is the realm of chemical kinetics, the subject of this experiment. In this experiment we will study the rate of oxidation of iodide ion by hydrogen peroxide which proceeds according to the following reaction: H2O2 (aq) + 2 I-(aq) + 2H+(aq) I2(aq) + 2H2O(l) By varying the concentrations of each of the three reactants (H2O2, I- and H+), we will be able to determine the order of the reaction with respect to each reactant and the rate law of the reaction, which is of the form: Rate = k [H2O2]x[I-]y[H+]z By knowing the reaction times (†t) and the concentrations of H2O2 of two separate reaction mixtures (mixtures A & B), the reaction order of H2O2, x, can be calculated. x = log(†t2/ †t1) / log ( [H2O2]1/[H2O2]2 ) The same method is used to obtain the reaction order with respect to I- (mixtures A & C) and H+ (mixtures A & D).
Chromatography techniques Chromatography is an analytical technique used for separation of different components from a given mixture. The basic principle is the characteristic distribution or partition coefficient denoted as Kd which is due to the specific distribution of the analyte between two immiscible phases, the mobile and stationary phases. In a chromatographic system the stationary phase may be a solid, gel, a solid mixture or a liquid mixture which is immobilized. The mobile phase may be a gas or a liquid and is passed through the stationary phase to which the analyte is applied before passing the mobile phase through it. The differential affinity towards the mobile phase and stationary phase of different components of the sample mixture
In this experiment, the first two reactions are exothermic so the temperature of the solution and container will rise and some heat will be lost to the surroundings. Purpose: The purpose of this experiment is to calculate the heat of formation of magnesium oxide by studying a series of reactions involving magnesium and magnesium oxide and using Hess’s Law. Hypothesis: If the heat of reaction is found for two equations, then Hess’s Law will be able to determine the heat of reaction of the desired product. Materials: • S... ... middle of paper ... ...actual heat of reaction for Part II was -146kJ/mole. The heat of formation found for the formation of liquid water was -286kJ/mole.
Its purpose is to correct for variations in sample injection size. It can also be used to correct for variations in peak retention times. Ion-exchange chromatography Partition chromatography in which the column has a bonded phase with a permanent or inducible charge opposite to that which attracts the target molecules. Compounds are eluted either with a counterion, salt, or pH gradients. Ion spray interface An atmospheric-pressure ionizing interface between the LC and MS modules.
These reactions are studied using DSC. In case of carbohydrates a phenomena called gelatinization (A physiochemical transformation due to heat treatment of carbohydrates) is studied using the DSC as the DSC uses enthalpy changes to study the phase transformation during these reactions. Applications in liquid crystals: Liquid crystal is transient state between the liquid and solid transitions, in which the molecules has the orderly arrangement of solid crystals as well as the flow properties of liquids. These states has anisotropic behavior and used for color sensors and color displays. The small energy changes from the isotropic phases (solids or liquids) to liquid crystals, are important for properties of liquid crystals.
They are: changing the nature of the reactants, changing the concentration of one or more of the reactants, changing the temperature at which a reaction is performed, changing the surface area of a solid reactant, adding a catalyst. I have chosen to study how the rate of reaction changes when the temperature of the sodium thiosulphate is varied. Before we could conduct the experiment there was some preliminary work to be done. This was to find out what amount of each liquid would be
C. Two coils are placed end to end with an iron rod placed through them. One is connected to a galvanometer the other to a power supply. The power supply is switched on and off. D. A large coil surrounding an iron rod is given a constant current. An aluminum ring with a slit to prevent complete current is placed over the rod.
The GCMS uses a combination of gas chromatography and mass spectrometry to measure and identify the ingredients present in the gas over the liquid, otherwise known as the “headspace.” In gas chromatography, the sample of gas is injected into a port where it is carried through a mobile phase. The mobile phase passes the sample through a long column that also contains a stationary phase. Gas chromatography, also called “elution chromatography” because the various components of the sample are eluted from the column sequentially, is composed of a stationary and mobile phase. The stationary phase is usually a viscous liquid with a high boiling point that coats the inside of the column and the mobile phase is generally a gas. In this experiment a 30 meter long capillary GC column was used and the mobile phase gas was Helium.