Finding the Ka of Ethanoic Acid Aim: ==== To find out the Ka of ethanoic acid, chloroethanoic acid and dichloroethanoic acid. Procedure: ========== 1. The pH meter is calibrated, using a buffer solution of accurately known pH. 2. 20.0cm3 of 0.10M ethanoic acid was pipetted into a conical flask. 3. 0.10M sodium hydroxide solution was titrated using phenolphthalein as indicator, until the solution was just turned pink. 4. A further 20.0cm3 of the same ethanoic acid solution was added to the flask and was mixed thoroughly. 5. The pH of the resulting solution was determined. Result: ======= Volume of NaOH used is recorded below: Trial (cm3) 1st time (cm3) Initial burette reading 3.55 18.4 Final burette reading 22.8 36 Titre 19.25 17.6 pH Chloroethanoic acid 3.0 Dichloroethanoic acid 2.2 Ethanoic acid 4.6 pH of chloroethanoic acid and dichloroethanoic acid is given by the teacher. Calculation: ============ Ka = 1. It is reasonable to make the following assumptions: [HX] » total acid concentration [X-] » total salt concentration because CH3COOH is a weak acid which is only slightly ionized and thus contributed only a little bit to total salt concentration. Therefore [HX] tends to total acid concentration, and [X-] is mostly contributed by the salt resulting from neutralization. Using these assumptions, we have: [H+] » Ka 2. If the concentrations of the acid and salt in the mixture are equal, then: [H+] » Ka ´ 1 [H+] » Ka 3. [H+] = Ka -log Ka = -log [H+] pKa = pH 4. The aim of neutralization is to neutralize all the acid, and make the concentration of the salt same as the concentration of the 20.0cm3 acid. Therefore the titre need not be exactly 20.
In the pH homeostasis lab, 6 experiments were conducted. The hypotheses were: If base is added to water then the pH will increase; If acid is added to water then the pH will decrease; If base is added to homogenate, then the pH will increase; If acid is added to homogenate, then the pH will decrease; If acid or base is added to buffer, then the pH will remain the same. After the experiments were conducted, the graphs were somewhat similar to the hypotheses.
We were then to make a base solution of 0.7 M NaOH. In order to standardize
...lsion had only come apart 2.5 mL. Listing them best to worst helped come up with the idea of putting together the two best ingredients in an emulsion. Whey Protein Concentrate did completely destabilize but it took all fifteen minutes to do so. Combining the two ingredients stabilized the emulsion the best because it stayed stable for all fifteen minutes.
Well, this looks like its using some calculations so what I would do is take my 0.045 M and equal it to the 0.25 mL of NH3 and multiply that by 45.0 mL and multiply it by 10 with an exponent of negative 3. Once all of that is multiplied together we should get an answer of 0.01135 moles of our HCI. Now we can find our “Concentration” Which means we would divide our moles (0.01125) to our vol in liters which is 0.025, once we do that, we get an answer of 0.045M of our NH3. Well, since we are on the topic of pH we know that we can use the formula: pH = -log (H3O+). Then what we would do is plug everything into the formula: pH equals -log (2.4 multiplied by 10 (with an exponent of -5). Once we find the answer to this and we add up all of our calculations, we can come to a conclusion that the answer is: 4.6197 as our pH.
Apparatus: * 1 measuring cylinder * 1 test tube * 1 stop clock * A large gelatine cube containing indicator and NaOH * Hydrochloric acid ranging from 1-3 molars * A scalpel Diagram: Method: * Take the large gelatine cube and cut into 15 equal pieces * Place on piece of the cube into the test tube * Measure out 10mls of HCl in the measuring cylinder * Pour the HCl into the test tube with the gelatine cube and start the clock * Time how long it takes for the pink colour inside the gelatine cube to completely disappear * You will also notice that the cube dissolves slightly * Record your results and repeat this same process 3 times for each molar of acid: § 1 molar § 1.5 molar § 2 molar
As, you can see pure solids and liquids are not included in the Ksp equation because they are already accounted for in the equilibrium constant. A Ksp with a large value has a lot of dissolved ions causing it to have
The Relative Formula Mass of an Unknown Acid Table of contents 1.1 Aim of the experiment 2 1.2 Introduction 2 1.3 Equipments and apparatus 2 1.4 Safety precautions 2 2.1 Procedure 3 2.2 Apparatus setup 3 2.3 Analysis 4 3.1 Implementing 5 3.2 Analyzing 6 4.1 Evaluation 8 4.2 Comparison between experimental Mr with value 8 of likeliest acid 4.3
The pH of the water can have a great impact on aquatic life and the ecosystem if it has sudden shifts. The pH was first checked with the pH paper resulting with an average of three trials resulting in a 7.1 reading. Next the pH was read with the pH meter, the result of the three trials yielded an average of 8.31 and the pH on the day of collection was 7.12. The 7.1 reading of the pH paper fell more closely to the sample day pH, with a range of 0.4. On the other hand the pH meter recorded the pH with a range of only .05 which is much closer and the 8.31 average more closely relates to previous data on the Chip-A-Waters River. The day of the sample selection there was rain that could have had acidity that made the sample day water more acidic than usual, and the pH paper readings could have been in error due to old pH paper and limitation of available reading range and significant figures. Though on the pH meter there was a found uncertainty of .19. When the buffer 7.0 pH solution was tested with the meter it read at a 7.19 pH. Both readings though vastly different fall between the normal range of 5.5-8.5
If an average of 5.00mL of NaOH were added, the concentration of ascorbic acid would have been 4.27g/L which is closer to the actual value (.360g/L). If an average of 15.00mL pf NaOH were added, the concentration
From looking at the results I can conclude that when the pH was 3 and
Compared to the 0.5 M hydrochloric acid that was less concentrated, the more concentrated 2 M hydrochloric acid c...
I decided to experiment with pHs within the range pH 2 to pH7, as I
Preparation of Ethanol and Ethanoic Acid AIM: To obtain pure samples of Ethanol (CH3CH2OH) and Ethanoic Acid (CH3COOH) from fermented Yeast (Saccharomyces Cerevisiae). BACKGROUND INFORMATION: The use of yeast in food production is the oldest and most extensive contribution made by any group of microorganisms. A most common substrate that yeast can work with is GLUCOSE. Glucose is a monosaccharide, which are sweet crystalline sugars that dissolve easily in water to form sweet solutions. Monosaccharides have the general formula (CH2O)n and consist of a single sugar molecule.
Titration is a technological process in which a solution, known as a titrant, is slowly and carefully added from a burrette into a fixed volume of another solution (known as the sample). In an acid-base titration an acid neutralizes a base or vice versa. This process is maintained untill the reaction between the titrant and the sample (acid and the base) is judged to be complete. The reaction is judged to be complete when the endpoint is reached. An endpoint in a titration analysis is referred to as the point at which no more titrant is added due to an observable colour change of an indicator. Indicators can be used to find an endpoint because they change colour when the pH of a solution changes and an endpoint in a titration is an empirical approximation of the equivalence point, which is the point of major pH change in the titration sample due to the fact that equal chemical amounts of reactants have been combined at that point. All indicators have a pH range, which is the range of pH values at which the colour of the indicator changes. Thus
For this experiment we used titration to standardize the exact concentration of NaOH. Titration is the process of carefully adding one solution from a buret to another substance in a flask until all of the substance in the flask has reacted. Standardizing is the process of determining a solutions concentration. When a solution has been standardized it is referred to as a standard solution. To know when a solution is at its end point an indicator is added to acidic solution. An indicator is an organic dye that is added to an acidic solution. The indicator is one color is in the acidic solution and another color in the basic solutions. An end point occurs when the organic dye changes colors to indicate that the reaction is over (Lab Guide pg. 141).