Turn on the hot plate to a medium heat. Wait until all the liquid has evaporated from the substance and then record the color of the dried substance. 6) Repeat steps 1-5 using each of the three other substances. NOTE: Make sure to wipe down all the materials before they are reused. Compounds | Solubility in Water | Solubility in Alcohol | Color if Soluble in H₂O | Conductivity(Scale 1-4) | Color When Dry | Melting Point (°F) | Sucrose | Yes | No | Transparent | Medium (2) | Brown | 366.8 | Sodium Chloride | Yes | No | Transparent | High (3) | Crystallized, Clear | 1474 | Sodium Carbonate | Yes | No | Mostly Transparent | High (3) | White | 1564 | Salicylic Acid | No | Yes | N/A | High (3) | White | 318.2
Three drops of phenolphthalein indicator was added into the HCl solution. The stopcock was opened and the NaOH solution was added into the HCl solution. The flask was swirled to mix the solutions and titrate to a faint pink end point. Recorded the final volume on the butret and used the final volume as a beginning volume to repeat the titration. At the second titration, the experiment was exactly the same as the first titration but the H2SO4 solution was used to instead of the HCl solution.
The paper was then put into a beaker of a hydrochloric acid, ethanol, and butanol mixture, being sure that the paper does not touch the sides of the beaker, and then topped. After the eluting solution has risen to within two centimeters of the top of the filter paper, the paper was removed from the beaker, dried, and was stained with a staining reagent solution containing potassium ferrocyanide and potassium iodide. This reagent forms colored precipitates or reaction products with many cations, including all of those used in this experiment. The distance of which the spots moved were determined by calculating the Rf value of each substance. The Rf value is determined by following formula: Rf=DL=distance component movesdistance solvent moves This experiment was successful overall, given a few errors.
Gravimetric Determination of Sulfate Purpose The purpose of this lab is to determine the percentage of sulfate in the hydrate by precipitating the sulfate as barium sulfate. Materials Filler paper Sodium sulfate Graduated cylinder Bunsen burner Watch glass Beakers (250 mL, 400 mL) Rubber bulb Graduated pipette Beaker tongs Funnel Filter Paper Sodium Sulfate Drying oven Wash bottle Stirring rod Silver nitrate Hydrochloric acid Distilled water Small test tube Procedures First, .4861 grams of sodium sulfate was placed into a clean 400mL beaker. Exactly 200mL of water and 1mL of HCl was added to the same beaker. A watch glass was placed on the beaker and the solution was heated using the Bunsen burner to a gentle boil. The watch glass was removed with the beaker tongs.
The unknown bacteria was taken from the NA agar slant and placed on an oxidase strip in a drop of distilled water. Within seconds the bacteria will turn purple if oxidized cytochrome oxidase is present, indicating a positive test. If no color change is observed, no cytochrome oxidase is present and the test is negative. My results for oxidase test were positive. To conduct the oxidase test I first obtained an oxidase strip.
Aim: | The aim of this experiment is to analyse a sample of vinegar and determine it’s concentration. | | | Hypothesis: | It’s expected that the aceatic acid will have the concentration of 0.1mol as this is the molarity of the NaOH as they have a 1:1 ratio of moles as it states in their chemical equations. | | | Apparatus: | * 1 x retort stand * 1 x retort burette clamp * 1 x burette * 1 x pipette * 1 x glass funnel * 2 x Conical Flasks * Sheet of filter paper * 200mL of 0.1 mol L-1 NaOH * 200mL of acetic acid of unknown concentration | | | Procedure: | 1. WARNING: Wear safety glasses and gloves! 2.
Wait 90 seconds for the light source to warm up, then fill a cuvette with distilled water and clean the flat, clear sides on the cuvette with a Kimwipe, removing dust and fingerprints before putting the cuvette into the instrument. Orient the cuvette so that the clear sides line up with the white arrow on the top of the spectrometer. Click “Finish Calibration”, then “OK”. Next, fill a cuvette with the “yellow” sample, repeating the steps to clean the clear sides of the cuvette with a Kimwipe to remove fingerprints and dust. Place the clean cuvette containing the “yellow” sample into the spectrometer, orienting the cuvette so that the clear sides of the cuvette line up with the white arrow in the cuvette.
100mL of distilled water was added to 10mL of vinegar and followed by 1mL of NaOH was pour into the solution. The average volume of NaOH required to neutralize the vinegar in each titration is 12.22mL .The experiment was completely and successfully done. Introduction Concentration of solution is the amount of solute in a given amount of solvent. A concentrated solution contains a relatively large quantity of solute in a given amount of solvent. Dilute solutions contain relatively little solute in a given amount of solvent.
Objective/Purpose The objective of a distillation process is to demonstrate methods for purification of volatile compounds (compounds that can be converted to gas phase at reasonable temperatures without decomposition) and to demonstrate that gas chromatography may be used to quantitatively determine the relative proportions of volatile compounds in each sample. Using three different separating and analyzing methods, we will be able to study what compounds were in our tomato paste. Materials - A glass distillation set up (including all of the little pieces) - Heating mantle - Thermostat - 100 mL round bottom flask - Beakers - Graduated cylinder - Stirring rod - TLC silica gel plates - Jar - Dichloromethane - 50/50 % hexane and acetone - Scale for weights - 7:1 hexane and dichloromethane mix for TLC - Tomato paste - Funnel Filter - Wool - Heating mantle Methods Weigh out approximately 10.00 grams of tomato paste. Then, retrieve 50/50% hexane/acetone. Next, get 2.00 grams of MgSO4 and combine it with the paste.
They were glucose, water, lemon juice, Coca Cola, egg batter, lemon-lime soda, diet lemon-lime soda, Kraft Italian dressing, skim milk and butter. The positive control was the glucose and the negative control was the water. Twenty drops of each sample of substance was added to the test tubes (in all there were 10 test tubes). After the solutions were added in their own test tube, 20 drops of Benedict’s reagent was added. Each individual test tube was placed in boiling water and removed after 5 minutes to test if