Ensure that solid is completely dissolved using a stirring rod. Next, a 10 mL beaker is filled with 3 mL of HCl and measure 10 mL of ionized water into a 140 mL beaker. Carefully turn on laboratory burner and start cleaning the Nichrome wire by dipping it into concentrated HCl acid. Hold the Nichrome wire on top of the flame and repeat the step until the wire doesn 't show any color. When the wire is clean, dip the wire again with some of the acid and dip it into the solution with the unknown compound in it.
This has to be prepared fresh. Procedure : (a) Preparation of calibration curve :(i) Pippet portions of standard NiSO4 solution into 100 ml volumetric flask. Use a series from 50 to 250 µg Ni. (ii) Add 25 ml 1.0 N HCl in 5 ml bromine water. (iii) Cool with cold running tap water and add 10 ml concentrated Ammonium hydroxide.
Mixing .20 milligrams of the commercial dye (red dye #3) with 250 ml of distilled water to get the initial concentration, the goal is basically to get the absorbency level below 1. Putting the dye solution in the blank cuvette and observe the absorbance level that it dorms. Repeat the steps five times making different dilutions to maintain multiple absorbance values. The second week was making another commercial dye solution and also testing the food dye brought into class. Calibrate the spectrophotometer the same exact way so that it does not mess up the calculations gathered.
To ensure the constant rate between HCl and propanone, solutions of propanone and HCl were prepared by following next steps: 100 cm3 of 2M propanone was poured in 250 cm3 measuring cylinder (± 1.5 cm3) 50 cm3 of 2M HCl was poured on the top of propanone (±1.5 cm3) The mixture was poured between two 250 ml flasks Flasks were closed with corks The process was repeated for 5 times but every time the propanone was diluted by 10%. The amounts of propanone, distilled water and HCl were following: 1st solution 2nd solution 3rd solution 4th solution 5th solution CH3COCH3 (cm3) (±1.5 cm3) 100 90 80 70 60 H2O (cm3) (±1.5 cm3) 0 10 20 30 40 HCl (cm3) (±1.5 cm3) 50 50 50 50 50 Therefore, the concentrations of propanone were 2M, 1.8M, 1.6M, 1.4M and 1.2M. Half of the solutions were put in fridge to cool down the solutions and others were left to stay in room temperature over night. Afterwards, for temperatures, 29°C, 37°C and 45°C, solutions were put into water bath to keep temperature constant. Measuring the
This experiment was done by using a mandarin orange. First, a mandarin orange was peeled off and squeezed to get 30ml of its juice in a beaker. Next, the juice was diluted with distilled water to get a measured volume of 50ml solution. After dilution, the solution was transferred into a 100ml Erlenmeyer flask. As it was done in the Experiment A, 20 drops of 0.2 M acetic acid and 10 drops of 2% starch solution was mixed well with the juice solution.
Standardization of NaOH solution Accurately weigh out a sample of approximately 0.3-0.4 g of primary standard potassium hydrogen phthalate, KHPh, which has been previously dried at 120°C. Do not use more than 0.4 g. To obtain an accurate mass, weigh the sample on weighing paper, slide it into a clean (but not necessarily dry) 250 mL Erlenmeyer flask and reweigh the paper to account for any KHPh that may remain on it. Dissolve the KHPh sample in about 50 mL of CO2-free water and add 2-3 drops of 0.1% phenolphthalein indicator. Begin adding the approximately 0.1 M sodium hydroxide solution from the buret while continuously swirling the flask contents. Do not open the stopcock completely.
The specimens were abraded with different grade emery papers, washed with distilled water, degreased with acetone, dried. The specimens were accurately weighted and were suspended by suitable glass hooks at the edge of the basin, and under the surface of the test solution by about 1 cm. Solution containing 0.5MHCl solution with and without various concentrations of Schiff base inhibitors. After 24 h exposure, the specimens were taken out rinsed thoroughly with distilled water, dried and weighted accurately. The weight loss (WL) in gm-2 h-1 was calculated using the following
The solution was warmed to 65oC with constant stirring on the magnetic stirrer till the solid was completely dissolved. Stirring was stopped and 0.4g of charcoal was then added to the solution. After which the solution was transferred to a Buchner funnel with a moist filter paper and the clear filtrate was collected via suction filtration. The residue was washed with warm solution of 10.035g of KI and 15ml of deionized water. 200ml of water was then added to the filtrate in a 500ml beaker with constant stirring.
The procedure was repeated thrice so as to obtain 3 readings per sample and the average was recorded as the samples pH. And lastly, after measurement of samples, the electrodes were rinsed with distilled water and blot dried to remove excess water and the electrodes were stored in the storage solution until use next time. And as for the measurement of electric conductivity, the meter was turned on and allowed to stand for about 15 minutes while the electrodes were in distilled water. The sample was mixed and poured into 50ml beaker. The electrodes were then rinsed with distilled water, and wiped before dipping into the sample.