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.
Write a hypothesis on what you think will happen when water is added. 3. Fill the test tube with two thirds of water and record the results. Copper (II) Sulphate Solution and Iron Nail 1. Record physical properties of the copper (II) sulphate
3 pipettes 3. 8 test tubes Procedures 1 Take two beakers, one filled with KI and the other with Pb. 2. Take one pipette and fill each test tube with different amounts of KI 3. Take one pipette and fill each test tube with different amounts of Pb 4.
Using a test tube holder, heat the R tube over the Bunsen burner, moving the tube in a circular motion until all the water has evaporated. The P tube will be carefully heated next, for about 10 minutes, until all the water has evaporated, and there is a white substance in the tube. After the water has evaporated, continue heating the tube over the burner for a minute longer, being careful to watch out for purple gas and yellow spots. The P tube
Jessica Atanova CHEM 104 lab 03/10/14 SUBSTANCES Granular zinc- gray crystal like | Iodine crystals- dark, circular, rock-like | De-ionized water: used for standard Zinc Ion procedure. | Materials: Boiling tube: for products. | Small test tubes: used to centrifuge the solution and precipitate | Graduated cylinder: used for measurement of water | Stirring rod: used various times to stir samples and solutions. | Spatula: used to measure and transfer the substances. | Centrifuge: used to isolate the solid from the solution | .
Different compounds boil at different temperatures because each has a different, characteristic vapor pressure: compounds with higher vapor pressures will boil at lower temperatures. Boiling points are usually measured by recording the boiling point (or boiling range) on a thermometer while performing a distillation. This method is used whenever there is enough of the compound to perform a distillation. The distillation method of
n (3) Solutions of aqueous sodium hydroxide and hydrochloric acid react to form water and aqueous sodium chloride. co NaOH(s) → Na+(aq) + OH–(aq) ∆H1 = ? Chemistry with Vernier py In this experiment, you will use a Styrofoam-cup calorimeter to measure the heat released by three reactions. One of the reactions is the same as the combination of the other two reactions. Therefore, according to Hess’s law, the heat of reaction of the one reaction should be equal to the sum of the heats of reaction for the other two.
For this particular exercise, you should be familiar with the following: • Sublimation: Many chemicals will sublime (phase change from solid state to gas state) provided the right conditions. Iodine, for example, sublimes at room temperature. A bottle of iodine will thus always have crystals forming around inside the bottle around the cap where sublimed iodine is being deposited (phase change from gas state back to solid state). Provided the proper equipment, chemicals that are being sublimed can be recovered. Decant(ing): Decanting is a way of separating a solid from a liquid.
Measure 50.0 mL of 2.0 M Sodium Hydroxide, NaOH, solution but DO NOT ADD YET. Click the Collect button to get the initial temperature of the HCl solution. After the first four readings have been recorded at the same temperature, add the NaOH solution. Make sure you have lowered the paper lid to keep from liquid coming out of the cup. Turn the Stirrer on, at a slow to medium speed.
Recrystallise the crude ester from methanol using a quantity of hot solvent approximately twice the minimum required for complete solution (This is to ensure that the phenyl benzoate does not separate until the temperature of the solution has fallen below the melting point of the ester). Phenyl benzoate separates as colourless crystals. 5. Determine the melting point of the product. Results : Yield (mass in gram) = __________________0.128 g_____________________ Melting point of pure phenyl benzoate (OC) = ___________70O______________ Melting point of your phenyl benzoate (OC) = ___________69O______________ Questions : 1.