For example, if you mix aqueous solutions of AgNO3 and NaCl, there are two new combinations of ions possible. The silver nitrate solution contains Ag+(aq) and NO3-(aq). The sodium chloride contains Na+(aq) and Cl-(aq). Possible new combinations of these ions are AgCl and NaNO3. Note: these formulas would have been written in the upper right hand corner of each box before beginning the lab.
Introduction In Chemistry 1211 lab the main objective was to identify the name of the unknown acid #2651145-PLF13 that was issued by the instructor. Melting point, titration of the unknown acid, calculation of equivalent weight, pKa, solubility tests, and properties of a hydrochloric acid; these procedures were used to characterize the unknown acid and then compared with known substances using GSU Chemistry department search engine. By doing this experiment he or she will develop an understanding of the properties of organic acids and differences between properties of a strong acid such hydrochloric acid. Experimental The first procedure to identify the unknown organic acid was finding the correct melting point. This was done by taking small amounts of the unknown acid.
The purpose of this lab was to find the molecular weight of two unknown substances by analyzing the freezing points in cyclohexane and to provide a visual representation of the freezing point depression effect. The theory of this lab is; by using measurements of mass of the unknown substances (solute) in correlation with the mass of the cyclohexane (solvent) and the freezing point constant of the solvent, you could determine the molecular weight of the solute by using the same math involved in deciding the freezing point of the solution/ The theory behind the visual of the FPD effect is that if one was to record the freezing point of a solution and two solutions of the same substances with more solute, one would see a visible drop in freezing point. The equations you needed for this lab were the freezing point formula for organic substances (ΔFp=(m)Kf) and the
Experiment and Observation: Please note that this procedure was adapted from the “Anions, Cations, and Ionic Reactions” LabPaq Lab manual (Hands-On Labs Version 42-0304-82-00-01, 2015) Please reference this manual for further information on the lab experiments. The first experiment was to perform a qualitative anion test. This was done by observation of chemical reactions and recording the results in Data Table 1. Using the information from the reactions we were able to identify unknown substances and recorded the results in Data Table 1. Data Table 1: Anion Confirmation Tests Chemical | Anion | Addition of AgNO3 | Addition of HCl | NaBr | Bromide | Cloudy white thin solution | Clear with sedimentation | Na2CO3 | Carbonate | Clear with white sedimentation | Bubbles, sedimentation combined to one formation | NaCl | Chloride | Milky white, white sedimentation | No visible change | Nal | Iodide | Pale green cloudy, sedimentation | Sedimentation dispersed to smaller pieces, solution clears in color | Na2SO4 | Sulfate | No visible changes noted | Milky white | Na2S | Sulfide | Clear with amber sedimentation | No visible Change noted | Unknown #103 | CarbonateNa2CO3 | Cloudy white thin solution | Bubbles, Sedimentation combined to one
Write a hypothesis on what you think will happen when mixed. 3. Combine the substances; record observations. Hydrochloric Acid and Magnesium 1. Add hydrochloric acid to a test tube.
How do you go from calculated/measured values to accomplishing stated purpose? (4 pts) The purpose of this lab is to determine the exact concentration of an unknown acetic acid solution. Titrations for two different reactions will be performed. Controlled volumes of one reagent are added to a flask containing the other reagent until the equivalence point of the reaction is reached, one between sodium hydroxide (NaOH) and potassium hydrogen phthalate (KHP) and the other between NaOH and acetic acid (CH3COOH). NaOH (aq) + KHP (aq) —› Na+ (aq) + K + (aq) + P2- (aq) + H2O (l) NaOH (aq) + CH3COOH (aq) —› Na+ (aq) + CH3COO- (aq) + H2O (l) The titration of NaOH with KHP will identify the concentration of the NaOH provided.
Chemistry Research essay With reference to nucleophilic substitution of haloalkanes, explain how rates data can be used to support a proposal for a reaction mechanism. (You should discuss the SN1 and SN2 mechanisms, the expected rate equations, suitable experiments which would confirm the rate equation and the link between the mechanism and the rate equation). The SN2 reaction is a type of Substitution reaction. The “N” indicates that it is nucleophilic substitution, and the “2” stands for bimolecular, which means that the order of the reaction is 2nd order. The general mechanism for SN2 is: Where LG stands for “Leaving Group” In a SN2 reaction, there are no intermediates formed, because the nucleophile attacks and the leaving group leaves simultaneously.
Identify the acid-base reactions from the reactions shown on this worksheet. 23. Think about the reactions for which we have written ionic equations. Which category of reactions would they best fit in to? Explain your answer.
,, II I Quantitative Measurements of the Solute Since the solute is the species involved in chemical transformations, our goal will be the determination ot"the number of moles of solute in a particular solution. To be definitive, you want to carry out a reaction that involves zinc iodide. Instead of getting the zinc iodide in the solid state, you go in the .lab and there is a flask that contains zinc iodide diss91ved in water (in the solution state). What might the label on the flask say that will tell you how much iodide there is in the water? · There are numerous measures of the amount of solute in solvent.
Methodology A survey was employed to find out the attitude towards chemistry and its prediction on achievement in chemistry. The attitude was measured using two scales of measurement namely Likert and Guttman. The selected topics in chemistry were periodic table (PT); chemical bonding (CB) and organic chemistry (OC).