The theoretical yield of aspirin is 5.77 grams. The percent yield of aspirin is 66.3%, which was calculated by dividing the mass of aspirin (actual yield) by the theoretical yield of aspirin times 100%. A side reaction happened when acetic anhydride and water produced acetic acid. This means that when using water to rinse out the Erlenmeyer flask,
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.
Extraction and Drying: Using a separatory funnel, the cooled filtrate was extracted with 10ml of methylene chloride. After shaking our mixture, we broke and dried our emulsion by slowing passing the lower layer through a cotton ball layered with anhydrous magnesium sulfate. The extraction process was repeated 2 more times for maximum collection of the organic layer. Distillation: The extracts were poured into a 50ml round bottle flask and connected to a simple distillation apparatus. To obtain the caffeine, the methylene chloride was removed from the extract, leaving us with our solid caffeine residue.
Data See Graphs Calculations The calculations consisted of the deviations to create the pH curve graph. The Ka was calculated by taking the –log of the amount of acetic acid added and squaring it then dividing it by the amount of solution added. The moles for the NaOH was calculated by taking .1 moles and dividing it by 1,000 mL and then multiplying it by the amount of NaOH added. For the Molarity, the mole-mole ratio is used to convert it. Conclusion The pH curve came out zig zagged.
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.
Controlled The controlled variables of the experiment were: A. The volume and concentration of the Hydrochloric acid. B. The concentration of the Sodium Hydroxide. Equipment List * Boiling Tube * 10 cm3 1mol dm-3 Hydrochloric Acid (HCL) * 15 cm3 1mol dm-3 Sodium Hydroxide (NaOH) * pH and Temperature Probes * Data Logger * Measuring Cylinder ‘ * Boiling Tube * Teat Pipette Method * Add 10ml of Hydrochloric acid, measured in a measuring cylinder, into a boiling tube.
I then allowed the remaining liquid to evaporate leaving behind salt. I poured the salt into the weighing dish and weighed the mass and calculated and recorded into table 1. Data Table 1: Experiment Data Grams Percent of Mixture Iron Fillings 0.9 gm 19.6 % Sand 1.4 gm 30.4 %
Calculate the Normality of the vinegar using the previously given equation. Na = (Nb)(Volumeb) (Volumea) C. Calculate the mass of the acetic acid in grams using the previously given equation. Massa = (Na)(GMWa) D. Calculate the percentage of acetic acid using the previously given equation. % Acid = Massa(g/L) x 100 1000g/L Discussion and Conclusion: Questions: LabPaq question guidelines: Answer questions A and G in the lab manual. Skip questions B, C, D, E and F in the lab manual, and answer these instead: A.
chemistry 1a. Urea [(NH2)2CO] is produced by reacting ammonia with carbon dioxide with the release of water. In one process 637.2g of ammonia is treated with 1142g of carbon dioxide A. Write a balance equation for the above reaction B. Which of the 2 reactants is the limiting reagent C. Calculate the mass of urea formed D. How much excess reagent is left at the end of the reaction E. If the actual yield of urea formed was 980g what is its yield % a. Ans.
When referring to mass sum of the atomic masses of the atoms represented by the formula of a molecular substance, the correct term used is A. atomic mass B. formula weight C. molecular mass D. molecular weight 12. A mole of CO2 contians A. 6.02 x 1023 ions C. 6.02 x 1023 formula ions B. 6.02 x 1023 molecules D. 6.02 x 1023 atoms 13. The mass of the products in a chemical reaction depends on the amount of A. excess reactant B. limiting reactant C. oxidizing agent D. reducing subtannce 14.