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.
D) the absence of charged molecules inside cells. Answer: C Page Ref: Section 3 11) The ________ pressure is the pressure required to prevent the flow of solvent through a solvent-permeable membrane that separates two solutions of different solute concentration. A) hydrostatic B) electromotive Answer: C Page Ref: Section 3 12 C) osmotic D) partial 12) Which is true about the solubility of electrolytes in water? A) They are all insoluble in water. B) They are usually only sparingly soluble in water.
This explanation can be demonstrated in table 3 also because the results of the reactions demonstrates that chloride reacted more by the color of the product compared to the color of chloride in the mineral oil. Also it also demonstrates that iodine is the weakest oxidizing agent because the results show that iodide didn’t change much from the color that it showed in the mineral oil. In example 6 we have shown the activity series for the halogens used in this
As the result of this, it can explain why the distance of fluorine in hexane is longer (1.3 cm) than the one in toluene (0.5 cm) and due to less non polar toluene has. Fluorenone can dissolve a little in toluene and slightly distance (1.0 cm) under toluene instead of does not move any more under hexane (0
Drops from the column were collected from this point on, using 10 collection tubes labeled 1-10. Each tube was used to collect approximately 5 drops of solution from the column in ascending numerical order. 25 microliters of the buffer solution were consistently being added to the column to prevent the column from drying. The 5 drops of solution in each of the clear collection tubes provides a way to observe the color saturation of the separated molecules. Two visible gradients of reddish brown (collection tubes 1-4) and pinkish red (collection tubes 6-9) were collected.
Experiment 2 Time | Observations | 5 minutes | Bubbled like sugar | Once salt water was added | Turned soapy white and thick | Equation: METHOD 1) Put 2 cm3 of castor oil into a 250 cm3 beaker and add 10 cm3 of 5mol.dm-3 sodium hydroxide from a measuring cylinder. (Take care when measuring this out and adding it to the beaker to avoid any drips and spills.) 2) Heat the mixture gently over a tripod and gauze, STIRRING CONSTANTLY with a glass rod (otherwise the mixture erupts). Allow to simmer (boil gently) for 5 minutes. Steady the beaker using
57 (1) (iii) A triglyceride is also formed in the reaction between glycerol and three molecules of oleic acid, C17H33COOH. State and explain which of the two triglycerides (the one formed from stearic acid or the one formed from oleic acid) has the higher melting point. (the one from) stearic acid; saturated / no (C to C) double bonds; chains pack close together / stronger intermolecular forces / van der Waals’ forces etc; 3 Ignore hydrogen bonding. If wrong choice made, only third mark can be scored. (3) (b) An oil sample containing 0.0100 mol of oil was found to react with 7.61 g of iodine, I2.
EXPERIMENT ( 3 ) Topic : The preparation of Phenyl Benzoate from benzoyl chloride Introduction : The preparation of phenyl benzoate (ester) from phenol and benzoyl chloride is an esterification. In this experiment, you are requested to prepare and purify phenyl benzoate by some techniques. Chemicals : Phenol, Benzoyl chloride, Dilute NaOH, Methanol Procedures : 1. Dissolve 1 g phenol in 15 cm3 dilute NaOH using a 50 cm3 quickfit flask. 2.
This solution was placed in a burette and 18.4 cm3 was required to neutralise 25 cm3 of 0.1 moldm-3 NaOH. Deduce the molecular formula of the acid and hence the value of n. 5. Sodium carbonate exists in hydrated form, Na2CO3.xH2O, in the solid state. 3.5 g of a sodium carbonate sample was dissolved in water and the volume made up to 250 cm3. 25.0 cm3 of this solution was titrated against 0.1 moldm-3 HCl and 24.5 cm3 of the acid were required.