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.
(If any unreacted zinc remained, 10 mL of hydrochloric acid would have been added and warmed.) Only the precipitate, now, remained in the beaker. A spatula was used to transfer it into was watch glass. The precipitate was washed with 5 mL of deionized water and decanted. The precipitate was then washed with ethanol and decanted.
Add 5 drops of MgCl2 to wells C1 and C2, 10 drops to C3 and C4 5. Add 1 drop of phenolphthalein to wells C1-C4, stir with toothpick 6. Add 5 drops of NaOH to C1-C4, stir and record observations 7. Add 1 drop of HCl to C1 and stir, add more drops until color changes, record observations 8. Add 1 drop of Na2 EDTA to C2 and stir, add more drops until color changes, record observations 9.
Obtain beaker filled with 250 mL of HCl and 5 pennies. 2. Get a pipette and remove 10 mL of that solution (HCl + Zn) and place it in a 100 mL beaker. 3. Add color indicator 4.
9) The number of moles of H2CO3 in the reaction NaHCO3 + C2H4O2 NaC2H3O2 + H2CO3 is also the number of moles of NaHCO3. 10) Calculate the number of grams of sodium bicarbonate by multiplying the number of moles of sodium bicarbonate by its molar mass. OBSERVATIONS BEFORE REACTION Total Mass: 165.93 g Total Mass: 165.93 g Mass: Alka Seltzer Tablet: 3.82 g Beaker + Vinegar: 162.11 g Temperature: 20.9 °C DURING REACTION Observations: Alka Seltzer is fizzing and dissolving into the vinegar Gas is being released as bubbles form; it’s carbon dioxide Looks like a nice glass of frothy beer AFTER REACTION Observations:
Wear safety goggles, apron, and gloves. 2. Obtain 30 mL beaker and 25 mL Erlenmeyer flask. 3. Pour 10 ml of 12 M HCl into 30 mL beaker and dilute to 3M 4.
* 3. 3.0 ppm standard: * 3.00 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 3. Cylinder was rinsed with distilled water. * * 4. Zero standard: 10 mL of distilled water was poured into a plastic cup labeled 0.
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. OSMOSIS CALCULATIONS: 1. Calculate the number of grams of NaCl needed to prepare 100 mL of a 280mOsm.L Solution. (280mosm/l) *(1L/1000mL)*(100mm/1)*(29mg/1mosm)*(1g/1000mg)=0.812g 2. Calculate the number of grams of glucose needed to prepare 100mL of a 280 msm/L glucose solution.
In the first part, five 100 mL flasks of 5 mL ligand solution, 5 mL 2 M sodium acetate, 4 mL 3 M NH2OH, and 1-5 mL Fe2+ solution are diluted with water. The absorption spectrum for varying concentrations of Fe2+ are measured using a spectrophotometer and the data is graphed in Excel. The slope of the line is ε in the Beer-Lambart equation A = εcl. In the second part of the experiment, eleven flasks containing diluted stock solutions of Fe2+ and ligand are mixed with 5 mL 2 M sodium acetate and 4 mL 3 M NH2OH and diluted with water. The absorption spectrum is measured using a spectrophotometer and the data is graphed in Excel.
If 0.100 mol of hydrogen iodide is placed in a 1.0 L container and allowed to reach equilibrium, find the concentrations of all reactants and products at equilibrium. 2 HI (g) === H2 (g) + I2 (g) Ke = 1.84(10-2 [H2]=[I2]= 1.07(10-2 mol/L, [HI]=7.86(10-2 mol/L 6. A 1.00 L reaction vessel initially contains 9.28(10-3 moles of H2S. At equilibrium, the concentration of H2S of 7.06(10-3 mol/L. Calculate the value of Ke for this system.