25 ml of diluted unknown acid solution to 100ml beaker by using 25 volumetric pipet. 10ml of deionized water and 3 drops of phenlpthalin indicator the beaker labeled as 3. Potentiometric titration acid solutions 125 ml of NaOH was obtaining in a beaker and 50 ml of NaOH transfer to buret the tip and the meniscus is at below 0 ml. one magnetic stirring bar placed in a beaker contain one of the known solution on a stir. The pH recorded by using pH electrode before adding NaOH.
A flame test was then conducted and the identity of the cation was determined. To determine the anion, the anion had to be separated first from the cation in the unknown compound. To do this, 0.1 grams of the unknown compound and 0.5 grams of sodium carbonate had to be boiled in 5 mL of distilled water. Once the solution boiled for 10 minutes, the precipitate was centrifuged out and the anion solution was left. 0.1 M silver nitrate was added to the anion solution and a precipitate was formed.
(c) Calculate the mass of water formed when 20 g of methane undergoes complete combustion. 6 Deduce the empirical formulae of the following: Moles and empirical formulae 1 Calculate the molar mass of these compounds. (Relative atomic masses H = 1; N = 14; O = 16; Mg = 24; S = 32; Ca = 40; K =39; Cr = 52; Fe = 56.) (a) calcium ethanoate, Ca(CH3CO2)2 (b) chromium sulfate Cr2(SO4)3 (c) magnesium hydroxide, Mg(OH)2 (d) potassium cyanoferrate(III), K3Fe(CN)6 2 When 2.4 g of magnesium
About 125 mL of standard HCl with a molarity of 0.3125 and was poured into a buret. An unknown sample of soda ash was obtained, and for each trial, a little over 1 g of the soda ash was quantitatively transferred into a wide mouth Erlenmeyer flask. About 75 mL of DI water and 5 drops of methyl purple indicator was then added to the soda ash powder. The solution was titrated once until the solution turned light purple, and then the flask was put on the hotplate for about 3 minutes of gentle boiling. After, the solution was titrated once more in order to reach the endpoint that was indicated by a bullfrog green color.
The mixture was decanted again in to the same beaker. Next, we added boiling chips to the liquid and evaporated the solvent over the hot plates under the hood. After the solvent was evaporated and the flask was cooled, we used a spatula to remove a small amount of the crude product and took its melting point. We determined the melting point range of the sample to be 43.0-46.0 degrees Celcius.The crude product was yellow colored when it was warm and orange in color when cooled and sticky. We then recrystallized our sample using 5 ml of warm acetone that was heated on a hot plate under a hood.
After which time, 2.1 mL of 30% hydrogen peroxide was added slowly followed by sodium hydroxide until a pH of 8 was observed. 20 mL of H20 and 10 mL diethyl ether were added to the flask. The contents were separated and the aqueous layer was rinsed with four 10mL portions of ether followed by 15 mL of sodium bicarbonate. The ether layer was dried with granular magnesium sulfate and then the solvent was removed by evaporation under reduced pressure. Lastly, the final product was analyzed by mass spectrometry and HNMR.
A melting point will be ran on the aspirin when completely dry. A capillary tube containing the dry aspirin will be placed into the melting-point apparatus. This process is to determine the melting point range of aspirin. First, a hot water bath was created with a 400. mL beaker on a hot plate. The temperature was raised to 70 degrees Celsius and 4.419 g of salicylic acid was measured out on a balance and transferred into a 125. mL Erlenmeyer flask.
2Al + Fe2O3 ( Al2O3 + 2Fe (26.98) ( 159.7) (101.96) 124 601 80 b. Al c. 234.3 d. 234 e. 34.1% 1c. A strip of zinc metal with a mass of 2.0g undergoes single displacement reaction with an aqueous solution containing 2.5g of silver(I) nitrate A. Write a balance equation for the above reaction B. Which of the 2 reactants is the limiting reagent? C. Calculate the mass of zinc (II) nitrate formed D. How much excess reagent is left at the end of the reaction?
Three titrations were performed to find the caplets mass. In these titrations we mixed a crushed up ASA caplet with 25mL of isopropyl alcohol. After adding the solution into a 250mLerlenmeyer flask, we added our second solution of NaOH until our solution turned to a light pink color, repeating the process three times. To find the mass of the caplet, we used stoichiometric calculations, based on our volume of solution used to dilute the caplet.
6 H2O) in 100 ml distilled water. (vi) 0.2(N) Sodium Hydroxide solution: Dissolve 8.0 gm sodium hydroxide in 1 l distilled water. (vii) Acetic acid: Dilute 1 part of glacial acid with 4 parts of water. (viii) Stock cyanide solution: Dissolve 2.51 gm potassium cyanide (A.R. Grade) in 1 l water, standardize this solution with 0.0192(N) silver nitrate solution.