Using a measuring cylinder, add 50cm3 of 1.0mol dm-3 sulphuric(VI) acid to the thyme extract in the conical flask. 8. Titrate the solution in the conical flask with the potassium manganate(VII) solution until a pale pink colour persists for 10 seconds. 9. Repeat the titration until there are two titres within 0.1cm3 of each other.
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.
Part B: The graduated pipet’s average density at 22.3 °C was determined to be 0.9785g/mL with a percentage error of 1.89% shows the graduated pipet to be more accurate and precise. Part C: Density of an unknown NaCl solution was measured and a calibration curve used to determine the percentage of NaCl by mass in the solution. y=0.007x + 0.998 which concluded that the concentration of the sodium chloride solution was 3.14%. INTRODUCTION Anything that you can see, touch, taste or smell, occupies space and has mass, it is called matter. Matter can be a gas, a liquid,
Labeled three test tubes 1, 2, and 3, and added 2 mL of milk to each. 5. Added 5 mL of Benedict’s Reagent to RS+, RS-, and tube #1, and boiled the tubes for three minutes. 6. Added one dropper full of Iodine to S+, S-, and tube #2, and agitated the tubes.
Experimental First, we weighed 2 samples, each has 1 gram of NaHCO3-KCl mixture Second, we put the samples in 2 crucibles (A and B) and weighed them. (crucible + sample; WA1 and WB1) Third, we heated both samples on a hot plate for 30 minutes. Fourth, we weighed the samples again (crucible + sample; WA2 and WB2) Lastly, we determined NaHCU3 percentage in the mixture using the following method: WA1 – WA2 x 100% 0.309 WA1 – WA2 x 100% 0.309 * * Results * Theorectically: * Discussion When sodium hydrogen carbonate is heated, new products are formed; sodium carbonate, water vapor, and carbon dioxide gas. This reaction may be presented in a different form with a measure of molecules: @Na2CO3 + H2O + CO2 (solid) (solid) (gas) (gas). Once the reaction of sodium hydrogen carbonate takes place, carbon dioxide gas is released, as well as water vapor.
5. 2mL of 3M HCL was mixed with 2mL of 1 M Na2CO3 6. 0.1 g of the catalyst MnO2 was added to a test tube containing 3mL of 3% H2O2. 7. 2 mL of a saturated calcium acetate solution was added to an evaporating dish.
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. Then, centrifuge it for 1 minute. On the side, weight a boiling test tube containing 2 boiling chips. When the separation is complete, remove the small test tubes from the centrifuge and decant the supernatant into the boiling test tube. Add 1 mL of deionized water to the small test tube containing the precipitate and mix it and centrifuge it for 60 seconds.
Silver nitrate tested for 2o and 3o alkyl halides expected in dibromocholesterol and sulfuric acid tested for alkenes expected in cholesterol. Bromination had 68.8% yield, debromination 73.7% yield, and overall 53.3% of commercial cholesterol was recovered as synthesized cholesterol. For commercial cholesterol, dibromocholesterol, and synthesized cholesterol, melting points were 145.2-148.1oC, 109.0-110.1oC, 146.3-148.2oC and retention factor (Rf) values were 0.69, 0.80 respectively. Chemical tests confirmed expectations, though some alkenes were present in dibromocholesterol. The similar melting points of the synthesized product as compared to the literature value; and similar Rf values for commercial and synthesized cholesterol showed the purity of
A) How many mosm solute will 1 gram of NaCl yield? Show your calculations. (1gNaCl/1)*(1000mg/1gNaCl)(2/58mg)=34.5mOsm. 3. Mixed Solutions: If 1 mmole of glucose (180mg=1mOsm) and 1 mmole of NaCl (58mg=2mmOsm) are put into a beaker and distilled water added to make 1 liter, the osmolarity is 3 mOSm/L.
Lab # 4 : The Redox Arena II Procedural Summary There will be three different sized test tubes that will be used in this experiment, a boiling tube, a large and small test tube. The boiling tube will be labeled “R” for “reactants”. A scale with a weighing paper will be tared before adding 2 grams of granular zinc (Zn), record the mass, and then move the zinc to the boiling (R) tube. Weigh out 2 grams of iodine crystals, record it, and this will be added to the R tube, with the zinc. The R tube will then be put in a large beaker.