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.
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.
Materials: 3 beakers Thermometer 3 Alka-Seltzer tablets Stopwatch Mortar and pestle Source of hot water Ice cubes Graph paper Procedures: Hot water- Run water from the hot tap until it is hot as possible Fill beaker with 80 mL of hot water Use thermometer to take temperature of water. Record in data table. Remove 1 Alka-Seltzer tablet from package Drop into the water. Measure the time it takes for the tablet to completely dissolve. BE READY WITH THE STOPWATCH.
Calculate the molarity of the original vinegar solution and its concentration in gdm-3, given that it reacts with NaOH in a 1:1 ratio. 7. 2.5 g of a sample of ethanedioic acid, H2C2O4.nH2O, was dissolved in water and the solution made up to 250 cm3. This solution was placed in a burette and 15.8 cm3 were required to neutralise 25 cm3 of 0.1 moldm-3 NaOH. Given that ethanedioic acid reacts with NaOH
of mixture Metal C 25.605g 24.6mL 25.2°C 100.5°C 28.7°C Calculations: Show your work and write a short explanation with each calculation. Part I: 1. Calculate the energy change (q) of the surroundings (water). We can assume that the specific heat capacity of water is 4.18 J/ (g · °C), and the density of water is 1.00 g/mL. (4 points) q = m × c × Δt Given: q=?
The following data were obtained when a sample of barium chloride hydrate was analyzed as described in the Procedure section. Calculate (a) the mass of the hydrate, (b) the mass of water lost during heating, and (c) the percent water in the hydrate. Mass of empty test tube 18.42 g Mass of test tube and hydrate (before heating) 20.75 g Mass of test tube and anhydrous salt (after heating) 20.41 g. Mass of the Hydrate is 2.33g. Loss (H2O) is 0.34g. Percent H2O in Hydrate is equal 0.34/2.33=14.6% 3.
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
The resulting product was [Co(NH3)5Cl]Cl2 and yield was 4.453g (.017 mol, 84.8%) Distilled water (25mL) was added to concentrated ammonia (5mL) in a 125mL Erlenmeyer flask. The reaction was heated and stirred, then [Co(NH3)5Cl]Cl2 (.0060 mol) was added to the solution. The reaction mixture was vacuum filtered, and the filtrate was cooled in an ice bath. 6M HCl was then added until the solution was neutral to litmus. NaNO2 (.0217 mol) was added to the solution and was allowed to react for five minutes.
Put exactly 5.0 mL of water in the 10.0 mL graduated cylinder. Record this volume in your data table (10.0 mL). Label the first pipet "Acid." To calibrate the pipet, fill it with LIU-2 water. Holding the pipet vertically, add 20 drops of water to the cylinder.
3. The mixture was poured into a beaker containing 25cm3 of ice – water and 2.5cm3 of concentrated HCl. Reaction mixture was left in ice – bath for 10 min. 4. Precipitated product was recovered by vacuum filtration and washed with two portions of 5 cm3 of ice – cold water.