Objectives: The purpose of this lab is to observe the reaction of crystal violet and sodium hydroxide by looking at the relationship between concentration and time elapsed of the crystal violet. CV+ + OH- CVOH To quantitatively observe this reaction of crystal violet, the rate law is used. The rate law tells us that the rate is equal to a rate constant (k) multiplied by the concentration of crystal violet to the power of its reaction order ([CV+]p) and the concentration of hydroxide to the power of its reaction order ([OH-]q). Rate = k[CV+]p[OH-]q To fully understand the rate law, concentrations of the substances must be looked at first. The concentration is measured in molarity.
Water samples from the Clark Fork have been taken and will be tested using both absorption and emissions spectroscopy in order to check the levels of group IA and IIA metal ions. When electrons in an element are excited energy is released that can be measured as light. Each element releases different levels of energy that are observed as different wavelengths of light. With the proper equations (E=hv and E=hc/⋋), emission spectroscopy can be used to find the wavelength and frequency of light emitted by the excited electrons. This will help determine the types of ions present in the water sample.
1) Jeffrey Cox CHE111-DL01 Lab number 10 Stoichiometry of a Precipitation Reaction 2) Purpose/ Intro. In this lab we will be able to calculate the actual, theoretical, and percent yield of the product from a precipitation reaction. We will thusly learn the concepts of solubility and the formation of a precipitate. A precipitate reaction is a reaction in which soluble ions in separate solutions are mixed together to form an insoluble compound that settles out of the combined solution as a solid. The solid then is the insoluble compound, called a precipitate.
The net reaction is: This reaction has been studied extensively and occurs for a wide variety of ketones. In general, the halogenations of a ketone can be represented as follow: The main evidence for any mechanism is provided by kinetic studies to determine an experimental rate law. Following the rate law of chemical kinetics, the differential rate equation for the reaction could be written as follow: Where k = rate constant; a, b,c are the orders of the reaction of S, I3-, and H+ respectively. I3- ion is the only coloured species in the reaction mixture, a spectrophotometer can is used to measure the change in its concentration, by applying the Beer-Lambert Law Where A= absorbance, ε= molar absorption coefficient, [I3-]= concentration and /= optical path length, that is, the distance travelled by the light through the solution. The ideal wavelength for the measurement of
The chart of reactivity tells chemists the comparable reactivity of elements. An element higher on the list is more reactive than the elements below it and can replace all elements below it. Overall, knowing the types of reactions and reactivity of elements both help predict products of a reaction. It is only with an understanding of these principles can one execute the Copper Cycle Experiment, for the experiment requires a good understanding of how mass can be altered via these reactions, but never destroyed. The experiment was performed to evaluate the skills of an individual to perform some lab skills like filtration and decantation and use these skills to understand the concept of percent yield.
CH 341 – Laboratory Techniques in Inorganic Chemistry Experiment 1: Identification of Stereochemical (Geometrical) Isomers of [Mo(CO)4(L)2] by Infra-Red Spectroscopy Abstract Purpose of this experiment is to prepareone isomer of molybdenum carbonyl complex, [Mo(CO)4(pip)2], and both possible isomers of [Mo(CO)4(PPH3)2] using convenient literature method. Examining the CO stretching region of the IR spectra, the isomers will be identified. Introduction Metal carbonyl considers as one of the most important class of organometallic compounds and many studies of their chemistry and their bonding characteristics has been done (2). Metal carbonyls were first considered as laboratory interests, but soon achieved huge industrial applications (6). The technique of infrared spectroscopy, in both the solid and solution phases, has proved to be of very useful in these studies.
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.
In this lab you will use a method called visible spectroscopy to determine the concentration of a solution of CoCl2. This method relies on the fact that colored solutions will
SEPARATION OF A MIXTURE OF SUBSTANCES LAB Purpose: Every chemical has a set of defined physical properties, and when combined they present a unique fingerprint for that chemical. When chemicals are present in a mixture, these unique physical properties can be utilized to separate the chemicals into their pure states. This experiment will give you experience in separating the components in a three-compound mixture; ammonium chloride, sodium chloride (table salt), and silicon dioxide (sand). Background: Because there are 3 components in our mixture, we will need several techniques to separate them. For this particular exercise, you should be familiar with the following: • Sublimation: Many chemicals will sublime (phase change from solid state to gas state) provided the right conditions.
Objectives 1. To find out the effectiveness of Likert scales on predicting achievement in chemistry. 2. To compare the effectiveness of Likert scales with Guttman scales in predicting achievement in chemistry. Methodology A survey was employed to find out the attitude towards chemistry and its prediction on achievement in chemistry.