Leading indicators

Pre-lab: An endpoint is indicated by some form of indicator at the end of a titration. The equivalence point is when the moles of a standard solution equal the moles of a solution of an unknown concentration. The endpoint of the solution should be a faint pink color. If the color is too dark of a pink that means that it is overly titrated. The independent variable is the amount of base being added to the solution. The dependant variable is the indicator. The constant variable is the acid…

Lactate dehydrogenase was assayed according to the method of King (1965) [21]. Reagents required: 1. 0.1 M glycine buffer: 7.5 g of glycine and 5.85 mg of sodium chloride were dissolved in one litre of distilled water. 2. Buffered substrate: 2.76 g of lithium lactate was dissolved in 125 ml of glycine buffer containing 75 ml of 0.1 N sodium hydroxide solution. This was prepared just before use. 3. 0.4 N NaOH. 4. 5.0 mg of NAD+ was dissolved in 1.0 ml of distilled water just before use. 5.…

can be determined by the white vinegar with the known concentration of sodium hydroxide from the previous lab. (Eq 2). CH3CO2H(aq) + NaOH(aq) = CH3CO2Na(aq) + H2O(l) (Eq 2) The purpose of indicator used to determine the end point of the reaction when both the reactants and product are colorless. The experiment goal of the lab is to determine the concentration of acetic acid (CH3CO2H) in the commercial white vinegar brand. Procedure and…

REFLECTIONS FOR LAB 4- FRICTION Lab 4.1 to 4.3 is about all the different frictions. We did 3 different labs. 4.1 was pulling a block across different surfaces and finding the difference in friction. 4.2 was about pulling multiple blocks across different surfaces and finding the difference in friction. 4.3 was about pulling blocks but in a bigger surfaces area. In Lab 4.1 we had to pull different blocks across different surfaces. The surfaces were a tabletop, wax paper, paper towel, fine…

Jessica Hill CHM 144M Section C Dr. Zhu Charles Dotse Aileen Decker 8 October 2015 The Quantitative Determination of an Acid in Carbonated Beverages Abstract: The basis of this lab was to juxtapose two different titration methods in their ability to identify the end point, calculate the molarity of citric acid in the two sodas, and apprehend the differences between polyprotic and monoprotic acids. In order to accomplish this, a traditional titration, with phenolphthalein, and a modern…

Calculations- Representative Fraction (RF): 0.92cm / 8.95cm = 0.10 Limitations- Ruler: +/- 0.05 cm One possible limitation for this experiment was the contamination of the chromatography paper by foreign amino acids. Any amino acids that our gloves came in contact with throughout the lab transfered over to the chromatography paper and appeared as purple spots, mostly on the border of it. Conclusion- The amino acids in unknown mixture A were Glycine and Valine. The amino acids in unknown…

(NaOH) as a titrant. In addition, the measured volume of the base consumed is used to reach the end point. Hypothesis: It is expected to, at the end point of the experiment, the solution within the conical flask with both the acid, base, and indicator, will turn from a clear transparent color to a permanent pink color due to it being…

bromthymol blue, and an elodea plant in an environment with light, it will result in a color change from yellow to greenish blue. Also, if a sealed test tube containing bromthymol blue and an elodea plant in a dark environment. The bromothymol blue, a pH indicator, was used to measure the amount of CO2 present in a given test tube. The controls being tested were two negative controls that consisted of one test tube containing bromothymol blue, CO2, and an elodea plant while being in a dark…

known concentration neutralizes an acid or base of unknown concentration. The neutralization of an acid or base in acid-base titration can be measured with either a color indicator or a pH-meter. For this experiment we are using a color indicator. The indicator phenolphthalein is used in experiment 1 and starch was use as an indicator in experiment 2.Phenolththalein is a colorless in acidic solution and pink in…

Abstract: The purpose of this experiment was to prepare and standardize a sodium hydroxide solution as well as determine the molar concentration in as strong acid and the percent by mass of acetic acid in vinegar. We used volumetric analysis, also known as titration, in both experiments. The average molar concentration for NaOH was 0.2749 mol/L while the average molar concentration of the acid solution was .2493 mol/L.The average percent by mass of acetic acid in vinegar was found to be 12.3 %…