A voltmeter was used to measure the electrical resistance of different solutions. * Experiment and Observation: The plastic and glassware used in this experiment was thoroughly washed with hot water and rinsed with distilled water. * * Part I: Preparation of Standard Phosphate Solutions 1. 1.0 ppm standard: 1.00 mL of 10.0 ppm phosphate solution was placed in a 25 mL graduated cylinder and diluted to exactly the 10 mL mark with distilled water then poured into a plastic cup labeled 1. Cylinder was rinsed with distilled water.
Procedure 1. Begin to prepare an EDTA solution. Weigh out 3.62-3.64 g of NaH2EDTA and record exact mass. Add the weighed amount to a 250 ml volumetric funnel carefully using a funnel Wash the funnel with water to ensure all of the solid is delivered to the flask Add 100-200 ml of water and mix. Enough water should be added so that the flask is full to the 250 ml mark Tightly wrap the top of the flask with a Parafilm when finished 2.
After that, dissolve the sample in 2 mL of deionized water and shake the test tube for 1 to 1 ½ minutes to dissolve the solid. Place another dry test tube in a 50mL beaker and weigh it. Find a bottle of barium iodide and record the name and molar mass. Then, weight out either anhydrous barium iodide or barium iodide dehydrate into this test tube and dissolve is it in 2 mL of deionized water. Pour the contents of one of the test tubes into the other and a reaction should occur and you should see a white precipitate of barium sulfate form.
Pour all the filtrate and washings into a 250cm3 volumetric flask. Make up to 250cm3 with 1.0mol dm-3 sulphuric acid(VI) acid. Stopper the flask and invert several times to thoroughly mix the solution. 5. Fill the burette with 0.005mol dm-3 potassium manganate(VII) solution.
White precipitate shows the presence of chloride (Cl-). Chloride anion equation: HCl(aq) + AgNO3 (aq) → HNO3 (aq) + AgCl(s). The nitrate anion test involves cooling a mixture containing 1 mL of test solution and 3mL 18M H2SO4. 2mL is poured down the inner test tube side and the presence of a brown ring shows nitrate (NO3-) to be present. The carbonate anion test mixes 1 mL of test solution and drops of 6M HCl.
Why is this necessary? Obtain an appropriate amount of 5.00 M NaCl and fill your 25 mL buret. Pipet a 20.00 mL aliquot of 0.100 M acetic acid solution into a 100 mL beaker, add a magnetic stirring bar, and then set up the titration apparatus as indicated in Figure 1. Record the initial pH and then begin titrating. You will titrate in 0.25 mL intervals for the first 2 ml and then in 1 mL intervals until a total of 6 mL of 5.00 M NaCl has been delivered.
-Use the titrations of the following chemical reactions: NaHCO3 + HCl (aq) NaCl (aq) + H2O (l) + CO2 (g) 2HCl (aq) + Na2CO3 (s) 2NaCl (aq) + H2O (l) + CO2 (g) Experimental procedure- Two Erlenmeyer flask must be labeled “unknown 1 and unknown 2”. Assure that all containers used are dried and cleaned properly. Two bigger flask are labeled “waste” according to each unknown. A pipette is set up and primed with HCl. The two unknown solids are weighed to a mass of 0.15g each.
Procedure: 1. Fill a beaker two-thirds full of water and add approximately 20 drops of IKI. Write down the solution's color and record the mass of the bag. 2. Do an initial Benedict's test on the 15% glucose/1% starch and the beaker solutions for glucose by putting some of the solution and a roughly equal amount of blue Benedict's solution in a test tube, placing the test tube in boiling water for 90 seconds, and observing whether or not the solution changes color from blue.
Try to rinse the precipitate in the funnel until the pink color is gone 12. Place funnel in the drier provided until it is completely dry 13. Let cool to room temperature 14. Weigh the funnel and record the weight 15. Subtract the weight of the funnel and the filter paper from this weight to get the weight of the precipitate Results: wt.
Care must be taken when squeezing the pipet bulb on the filter pipet. Too much pressure might cause the filter to leak or fall off. Add about 2 mL of fresh tert-butyl methyl ether to the solid in the RB flask, warm briefly, let the solids settle for a minute, and pipet the liquid to the centrifuge tube as before. Again allow the solids to settle briefly in the centrifuge tube, then filter the liquid through the pressure filtration apparatus, into the same 25 mL Erlenmeyer flask. Doing a rinse such as this helps to ensure that any trimyristin that was left behind in the RB flask and centrifuge tube is not lost, thereby helping to ensure that