Introduction In the late 1700’s, Jeremias Benjamin Richter defined stoichiometry as the "art of chemical measurements, which has to deal with the laws according to which substances unite to form chemical compounds." In this exercise, we combined copper(II) sulfate pentahydrate with two moles of sodium hydroxide which produced copper(II) hydroxide and sodium sulfate (CuSO4 + 5H2O +2NaOH Cu(OH)2 + Na2SO4). We then dissociated copper(II) hydroxide to produce copper(II) oxide and water (Cu(OH)2 CuO + H2O). The objective of this exercise is to perform a simple chemical reaction where the concept of stoichiometry is put into practice (2). The goal of this experiment was to make Copper(II) oxide. Copper(II) oxide is an important substance in …show more content…
To do this you first have to place the weighing boat on the scale and hit tare, so it reads zero and then place copper(II) sulfate pentahydrate on the weighing boat. Transfer the copper(II) sulfate into a 250-mL beaker. Rinse the weighing boat with 5 mL of purified water in small quantities to rinse off leftover chemical into the beaker. Spin the beaker gently to dissolve the solid. Rinse the sides of the beaker with small amounts of the 5 mL of purified water. Measure and carefully add 10 mL of 6.0 M NaOH to the beaker and cautiously swirl to mix. Take a watch glass and set it over the beaker to cover. Heat gently on a hot plate to the boiling point of the solution. If any spattering occurs while heating, wash the solid back down into the solution using a wash bottle. Heat the solution until all the blue solid has been decomposed to the dark colored copper(II) oxide. Allow the mixture to cool before filtering. Fold a piece of the Whatman filter paper while waiting for the mixture to cool. To fold the Whatman paper, you first fold it in half, and then in half again. Open it by grouping three of the folds at the opening together and leaving one on the other …show more content…
This means that there were a few errors made during the exercise. While we cannot pin point the main reason why the percent yield is so high, there’s a few possibilities. First, it might not all be CuO, there could have still been water in the filter paper and precipitate when we took it out of the funnel which would cause the mass to change and affect the percent yield. But the main possibility as to the high percent yield is that there is still some Cu(OH)2 in the precipitate that never got broken down when heated which affected the percent
An error that could have been present during the lab includes not letting the zinc react completely with the chloride ions by removing the penny too early from the solution. For instance, the percent error of this lab was 45.6%, which was determined by the subtraction of the theoretical percent of Cu 2.5% and the experimental percent of Cu 3.64% and dividing by the theoretical percent of Cu 2.5%. This experiment showed how reactants react with one another in a solution to drive a chemical reaction and the products that result from the
2. Add 8cm³ of sodium carbonate to each tube using a measuring cylinder. 3. Measure out the strontium nitrate for each boiling tube and add it (boiling tube 1 contains 1cm³, test tube 2 contains 2cm³ and so on). 4.
Prepare the standard solution of FeSCN2+ pipetting 18 mL of 0.200 M Fe(NO3)3 in a 20 * 150 mm test tube labeled five. Pipet 2 mL 0.0020 M KSCN into the test tube and stir. 6. Prepare a blank. Fill the plastic cuvette ¾ full with distilled H2O. Properly clean the cuvette and handle only by the top ribbed edge while wearing gloves.
After 1-2 minutes results were recorded in a observation table. The independent variable in this reaction is the amount of copper wire, magnesium ribbon, and zinc metal (powder form) and the 1/3 filled wells of copper (II) nitrate, magnesium nitrate, or zinc nitrate. The dependent variable in this reaction is the reaction that occured between the metals and the solution. Part B: Using the same experimental design as part A, three drops of sodium
Afterwards, 0.1ml of ferroin solution (as an indicator) was added. Next, titration was performed. The contents in the conical flask was titrated with 0.1M ammonia cerium (IV) sulphate until a yellow solution was produced. The experiment was then repeated without sample B (only the H2SO4 and water in the proportion 3:7, 6ml acid 14ml
3mL of the liquid in each of the vials were added into cuvettes and measured in the spectrophotometer. Before each time point the photo spectrometer was zeroed using a cuvette with 3mL of distilled water. If any of the results were considered unusual the machine was zeroed again and the sample was retested. The results from the spectrophotometer test were recorded in a table. The experiment was repeated six times to gain a sample size of six.
3. Using the 100 cm3 measuring cylinder, measure 100 ml of water and pour it into the Styrofoam cup with the lid. Record the new mass displayed. 4. Place the Styrofoam cup with the lid into the beaker.
As seen in table 1, the theoretical yield was .712 g of C_17 H_19 NO_3. The % yield of this experiment was 7.51 % of C_17 H_19 NO_3. . This low yield can be explained from a poor recrystallization technique combined with potential contamination. Throughout the experiment, the mixture changed color from green, orange, to yellowish lime, and eventually clear.
Weighed 1 gram of NaC2H3O2 and mixed it with ionized water. Boiled 12 mL of 1.0M Acetic Acid added into a beaker containing the sodium carbonate on a hot plate until all the liquid is evaporated
Copper Cycle Lab Report Ameerah Alajmi Abstract: A specific amount of Copper will undergo several chemical reactions and then recovered as a solid copper. A and percent recovery will be calculated and sources of loss or gain will be determined. The percent recovery for this experiment was 20.46%.
15) After each cuvette was tested, place the distilled water sample (Cuvette zero) to reset the spectrometer and to ensure that the scale is calibrated and repeat for each cuvette test. Data/Results: Tube Number Concentration Of CoCL2 (Mg/ML) CoCL2 Stock (ML) Distilled Water (ML) Spectrometry Reading at
Add 50 to 100 ml of freshly neutralized hot ethyl alcohol and about one ml of phenolphthalein indicator solution. 4. Boil the mixture for about five minutes and titrate it against the standard alkali solution while shaking vigorously during the
Weight a clean, dry, porcelain evaporating dish on the electric balance and record this mass on an appropriate data table. If the crucible needs to be washed before use, then heat the crucible in the Bunsen burner flame for a few minutes and remove any residual water. Then allow it to cool before continuing. Fill the crucible about 1 gram with the hydrated salt and reweight. Assemble the ring stand, ring, clay triangle, and Bunsen burner
Once dissolved, fill the rest of the volumetric flask up to the line on the neck of the flask. Again mix the solution. Use four, 10mL volumetric flask, and label them from 1-4. Add approximately 2mL of copper sulfate pentahydrate into flask 1, 4mL to flask 2,
Rinse the Erlenmeyer flask with about 10 ml of solvent and pour the solvent through the funnel, too. Remove the funnel, add two or three boiling chips and reattach the thermometer and adapter to the still pot. • Discard the magnesium sulfate remaining in the Erlenmeyer flask by dissolving it in tap water and pouring the solution down the drain. • Before beginning the distillation, weigh a clean, dry 1 narrow mouth screw cap bottle on a balance. Remove the cap of the bottle, and insert the clean, dry plastic long-stem funnel in the neck of the bottle.