Then, reweigh the cylinder to the nearest milligram. Calculate the density of the water then compare the measured density of the water with the value from the handbook for the temperature of this lab experiment. Now grab an unknown liquid and record the ID number and determine and verify the density of the unknown liquid. The same method is to be used as described for water. III.
The purpose of this lab is to observe the reaction between hydrochloric acid and magnesium metal. When the substances are reacted over water, the products produced are a salt in aqueous solution and a gas. While the salt remains in the water as part of a solution, the gas produced will float to the top. Though water vapor pressure will affect the pressure of the gas in the eudiometer, it is possible to apply Dalton’s law of partial pursues to find the dry pressure of the gas. When the dry pressure is determined, the volume of the gas at STP can then be determined and what the experimental volume of one mole of the gas would be at STP.
Numerous tests have been created to measure the magnitude of said concentrations. The tests range from simply evaporating the solvent and examining the leftover nonvolatile residue that remains, which is known as the total dissolved solids (TDS) of the sample, to chemical titrations using indicators (EDTA), to advanced spectroscopy of the sample using emission spectrums to determine ion absorbance values (AA Spectroscopy). There are a few differences between AA Spectroscopy and EDTA titrations when it comes to determining water hardness as both tests use different techniques. AA Spectroscopy is used to determine the concentration of metal ions in a water sample. A spectrophotometer is used to read the absorbance value of the cations in a flame that emits a photon read by the machine.
Purpose: The purpose of this lab is to titrate an unknown solid acid (KH2PO4) with a standardized sodium hydroxide solution. After recording and plotting the data, the acid’s equivalence point will be recorded once the color changes. Using the equivalence point, the halfway point will be calculated, which is used to determine the acid’s equilibrium constant. The acid’s calculated equilibrium constant will be compared with the acid’s established pKa value. Eventually using the NaOH and the acid’s consumed moles, the equivalent mass will be determined.
One mole of Ammonium dichromate will give rise to one mole of 1 mole of Chromium (III) oxide and 1 mole of Nitrogen gas and 4 moles of Water is gaseous phase. To convert these into formula units, 1 mole of any compound will equal 6.022X1023. So based on this, 1 mole of Ammonium dichromate is 6.022X1023 formula units. 1 mole of Chromium (III) oxide is 6.022X1023
Moles extrapolated from the titration curve were used to find the molecular weight of the unknown amino acid, along with the pkas and the pI. This information when compared to the literature values of Gly, L-ala, L-ser, and L-asp (of which the unknown was one of) led to the conclusion that the identification of unknown C was likely to be L-Aspartic Acid. The literature values agreed with some deviance from the experimental values, which were likely due to experimental errors. This showed that we can prepare a buffer using an amino acid and use the titration curve of that buffer to identify the unknown amino acid. Results Data
Procedure First, five standard solutions were made using 10-, 20-, 30-, 40-, and 50-mg/L of caffeine. The 10-mL solution was created by mixing 10-mL caffeine standard and 10.0-mL 0.10M HCl and diluting to 100.0-mL. This same procedure was used to make the rest of the solutions. Then 6.0-mL of soda, with the carbon dioxide removed, was placed in a 100-mL volumetric flask along with 10.0-mL 0.10m HCl and diluted. Then, the UV absorbance of the five standards was taken.
The volumetric flask was then filled up to its 100 mL mark with deionized water. The buret was washed out with dionized water and then with the strong base NaOH before being filled up with NaOH. About 20 mL of the unknown weak acid was pipetted into a beaker. The starting volume of the NaOH in the buret was recorded before about 4 mL of the strong base was titrated into the weak acid solution. The final volume was recorded.
Abstract In this experiment, the reaction kinetics of the hydrolysis of t-butyl chloride, (CH3)3CCl, was studied. The experiment was to determine the rate constant of the reaction, as well as the effects of solvent composition on the rate of reaction. A 50/50 V/V isopropanol/water solvent mixture was prepared and 1cm3 of (CH3)3CCl was added. At specific instances, aliquots of the reaction mixture were withdrawn and quenched with acetone. In addition, phenolphthalein was added as an indicator.