Purpose: The purpose of this lab was to identify what the unknown acid though doing pH titration. To obtain the unknown acid, the KA value of the acid was determined through experimentation of the reaction (a quantitative method). Another method to obtain the unknown acid solution is through qualitative observations. The unknown number of the solution was 152.
Introduction:
This lab was to determine the derivative of the acetic acid that was contained in the unknown acid solution. The derivatives of acetic acid were: monochloroacetic acid, dichloroacetic acid, and trichloroacetic acid. The structural formula for acetic acid included carbon atoms, hydrogen atoms, and a carboxyl group. When more chlorine atoms were added in the chemical
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Qualitative identification of unknown:
There were three indicators used which contained four different tubes of acid going from the weakest to the strongest. The indicators included: thymol blue, malachite green, and crystal violet. The unknown solution was poured into three test tubes where each indicator was used. The unknown acid solution colour was then compared to the display of the acid solutions.
Quantitative analysis: The first step of this part of the experiment was to calibrate the pH meter. This was to standardize it in order for it to read the values of the pH. The buffer solutions, which were used, were pH 4, pH 7, and pH 10. It was important to not contaminate the calibration solution in order to ensure that there would be no alteration of the pH. Once the calibration was done, the titration part of the experiment was conducted. A 25 mL volumetric pipette was used to transfer 25 mL of the unknown solution into a 100 mL solution. Also, and 50 mL volumetric pipette was used to transfer 50 mL of NaOH solution to put into the titration. Once these two steps were done, the actual titration occurred where it started with 0.25 mL of the first 3 mL, then proceeded to 1 mL of increments until the next 20 mL, and then essentially to one drop increments in order to obtain the equivalence point. The titration was done for both the HCl solution and the unknown
Marwah Alabbad Post lab 10/21/15 Question 1: 1. Experiment 1: Number of trails NaOH concentration (M) Volume of HCl solution (mL) Initial volume of NaOH(mL) final volume of NaOH(mL) The volume of NaOH to titrate HCl (mL) Concentration of HCl (M) 1st 0.1023 25.0 10.05 36.12 26.07 0.085 2nd 0.1023 25.0 5.74 31.40 25.66 0.105 3rd 0.1023 25.0 9.84 35.52 25.68 0.105 First trail calculation: 0.02607L× (0.1023mole NaOH/1L)×(1 mol of HCL/1 mol of NaOH)×(1/0.025)= 0.085M of HCl
Identification of an Unknown Compound using Quantitative and Qualitative Analysis Lauren Tremaglio Chemistry 1011 Lab, Section 16 Instructor: Steven Belina October 3, 2014 Our signatures indicate that this document represents the work completed by our group this semester. Experimental Design and Discussion of Results The objective of this experiment was to identify an unknown compound through quantitative and qualitative analysis. In order to find the identity of the unknown compound, an initial qualitative test for solubility was performed.
The unknown compound was first reacted with an acid. To begin, 0.50 grams of KCl was mixed with 5 mL of water. Then, 1 mL of 6 M H2SO4 was added to the solution. Secondly, the unknown compound was reacted with a base. Exactly 0.50 grams of KCl was mixed with 5 mL of water, and 1 mL of 1 M NaOH was added to the solution next.
The compounds tested in included the unknown, Calcium Nitrate, Calcium Chloride, Calcium Carbonate, Sodium Chloride, Potassium Chloride, Magnesium Chloride, and Ammonium Chloride. The next test was the pH test. In this test, the aqueous solutions from the flame tests were used again. A piece of pH paper was dipped into the aqueous solutions, a different piece for each solution. The ensuing coloration of the paper was compared to the pH scale and the
3. Upon adding 20 drops of NaOH, a white precipitate was formed signifying acidic impurity. In the second NaOH mixture, about 20 drops were administered and no precipitate formed indicating that the ample is more pure than before. Data: Weight of flask = 75.10 grams Weight of the flask with solids =
In this lab, we tested 8 known ingredients to find what ingredients was in our unknown A and unknown B medications. We first tested the water solubility of our knowns and unknowns. We found that of the knowns, cornstarch and acetaminophen were the only ones not water soluble. The unknowns were also not water soluble. Th next test was the pH test.
Abstract In this experiment, the isolation, characterization, and determination of concentration and purity of deoxyribonucleic acid or DNA from Allium Cepa or onion was performed. DNA was isolated through the use of a homogenizing solution. The absorbance ratio was 1.5, which indicates protein contamination. Moreover, the characterization of its components was conducted through the use of different chemical tests.
Introduction: In this task I will be researching the effect that acid rain has on the rate of plant growth. Acid rain is any type of precipitation with a high pH, with high levels of nitric acids. The reason why I had chosen this topic was because acid rain seems to have a great effect on the effect of plant growth, and plants play a very important role in our ecosystem. Acid rain is a major problem in our environment when we are not able to neutralize the acidity.
Commercial vinegar, Yamaha brand 0.1 mol/dm3, NaOH soloution Phenolpthalein indicator soloution (50.00 ± 0.5 cm3 ) cm3 burrete (250.00 ± 0.5 cm3) volumetric flask a (250 cm3± 0.5 cm3)
Acids are proton donors in chemical reactions which increase the number of hydrogen ions in a solution while bases are proton acceptors in reactions which reduce the number of hydrogen ions in a solution. Therefore, an acidic solution has more hydrogen ions than a basic solution; and basic solution has more hydroxide ions than an acidic solution. Acid substances taste sour. They have a pH lower than 7 and turns blue litmus paper into red. Meanwhile, bases are slippery and taste bitter.
Practical I: Acid-base equilibrium & pH of solutions Aims/Objectives: 1. To determine the pH range where the indicator changes colour. 2. To identify the suitable indicators for different titrations. 3.
Introduction Buffer is a solution that resists a change in pH when bases or acid are added. Solutions that are acidic contain high concentrations of hydrogen ions (H+) and have pH values less than seven. Buffer usually consist of a weak acid, and its conjugate base or a weak base and its conjugate acid. The function of buffer is to resist the changes in hydrogen ion concentration as a result of internal and environmental factor. This buffer experiment is important so that we relies the important of buffer in our life.
The chemical equation for this experiment is hydrochloric acid + sodium thiosulphate + deionised water (ranging from 25ml to 0ml in 5ml intervals) sodium chloride + deionised water (ranging from 25ml to 0ml in 5ml intervals) + sulphur dioxide + sulphur. As a scientific equation, this would be written out as, NA2S2O3 + 2HCL + H2O (ranging from 25ml to 0ml in
The mass of vinegar used during the experiment was 4.108 grams. It was determined that there were .003129 moles of CH3COOH in the vinegar sample. Using this information and the molar mass of CH3COOH, which was 60.05 g/mol, the mass of acetic acid in the vinegar was calculated: 4.Vinegar is a 5% aqueous solution of acetic acid. Since the mass of acetic acid within the vinegar was calculated as .18789 g in step 3, the percent of CH3COOH was calculated using the following equation: To calculate the percent error, the experimental value of 4.5% acetic acid in vinegar was subtracted by the theoretical value of 5% and divided by 5% to yield a percent error of 8.54%. The following is a copy of the calculations done using decimals: 5.The equivalence point of the titration curve measured in step 1 was 25.25 mL of NaOH.
That caused a new initial reading of NaOH on the burette (see Table1 & 2). The drops were caused because the burette was not tightened enough at the bottom to avoid it from being hard to release the basic solution for titrating the acid. The volume of the acid used for each titration was 25ml. The volume of the solution was then calculated by subtracting the initial volume from the final volume. We then calculated the average volume at each temperature.