Lab Report: Accurate Measurement of Mass and Volume

Procedure: I used a ruler, thermometer, and scale to take measurements. I used a graduated cylinder, short step pipet, scale, and ruler to determine volume and density. I used a volumetric flask, graduated pipet, pipet bulb, scale, and glass beaker to determine concentrations and densities of various dilutions.

As a group, we obtained our salt mixture of calcium chloride and potassium oxalate, and weighed the mixture. We were able to make an aqueous solution from the mixture and distilled water. We boiled and filtered off the solution, leaving the precipitate. Once the precipitate was dried overnight, it was weighed and the mass was measured. Then we calculated the moles of the precipitate.

In this task the concentration of an unknown sample of copper sulphate using colorimetry was used to find the concentration. In this investigation copper sulphate was used which is CuSO4.5H20 as a formula. To make a standard solution which was 1M, the same clean equipment was used to make up the standard solution as used to make sodium carbonate. However there was one difference and that was that the hot distilled water was used to dissolve the copper sulphate crystals. There had to be enough hot water in order to dissolve the crystals into the beaker and then add cold distilled water to cool the solution.

The purpose of the experiment is to cycle solid copper through a series of five reactions. At different stages of the cycle, copper was present in different forms. First reaction involves reaction between the copper and nitric acid, and copper changed from elemental state to an aqueous. The second reaction converted the aqueous Cu2+ into the solid copper (2) hydroxide. In the third reaction Cu(OH)2 decomposed into copper 2 oxide and water when heated. When solid CuO reacted with sulfuric acid, the copper returned to solution as an ion (Cu2+). The cycle of reactions was completed with the reaction where elemental copper was regenerated by Zn and Cu

Washing of the copper is necessary in this experiment to separate the iron from the copper and make sure the iron is not counted in the mass of the copper.

Then 8.0g of copper sulfate crystals were placed inside the beaker and the mass was recorded for the actual crystals. 50 mL of water was added to the beaker with the crystals. The ring stand was set up with the wire mesh on it and one partner should place the mixture in the beaker on it should be heated without letting the mixture boil. Stir the mixture and heat until the crystals are dissolved. While one partner does this, the other should obtain 1.5g of iron filings in a measuring cup and records the mass. Then the iron filings should be added small amounts at a time to the heated solution. Stir continuously until all the mixture is added to the beaker. Then it sat for 10 minutes and observations were recorded. Record the mass of a filter paper and set up a filtration apparatus with the filter paper in a funnel over an Erlenmeyer flask. Decant the liquid through the paper slowly trying not to allow any solid to get on the filter paper. Then with de-ionized water, rinse your solid in the beaker and let the solid settle then decant the liquid. Repeat the washing twice more and in the last time guide all the solid into the filter paper. Then place the filter paper on a watch glass and then into a warm oven to dry. After it is cool, record the mass of the watch glass, filter paper and solid. If there is not enough time to cool, you may have to do it the next

Introduction: Accuracy and precision were the major aspects of the lab. Accuracy is how close the average of the measured values are to the actual value. Precision is the closeness of repeated measurements. In the lab, the aim was to get as close as possible with both accuracy and precision when determining the mass and volume of the spheres. The mass was determined by weighing the spheres on the Analytical Scale and Triple Beam Balance Scale. The volume is determined by measuring with a ruler and by water displacement. The standard

In the fourth stage of this experiment, the density of a gas was determined. A 250ml flask was weighed with an empty rubber balloon and the mass was recorded.

Before the synthesis of the Copper Iodine Compound, the identities provided (CuNO3)2 and Nal weighed 1.65 g and 4.7 g, respectively. After being weighed, the (CuNO3)2 exhibited a blue color, while the Nal, through observation, was a white color. However, when both identities were combined, the product turned into a brown and red rocky material. Once 20 mL of deionized water was added, the product quickly turned pale pink paste. After the solution was repeatedly washed with a total of an additional 100 mL of deionized water, the product was powdery and pink with small grains, and was left to air-dry. Once the product was air dried, it was observed to be a pale pink color, while the filter paper was stiff as the product was hard and dry. Therefore, the solid was scraped off onto a recrystallizing dish. However, the mass of an empty recrystallizing dish needed to be recorded in order to compare how much of the synthesized copper iodide was obtained. Within this case, the empty recrystallizing dish used weighed 32.01 g, the product on the empty dish weighed 1.03 g, having a total weight of 33.04 g.

XIV. Record your observations of the dried, cooled copper metal and weigh the recovered copper.

Apparatus: Spectrophotometer (UV-1201), cuvettes, water bath (set at 37°C), 200µl and 1000µl micropipettes and test tube

The lab performed required the use of quantitative and analytical analysis along with limiting reagent analysis. The reaction of Copper (II) Sulfate, CuSO4, mass of 7.0015g with 2.0095g Fe or iron powder produced a solid precipitate of copper while the solution remained the blue color. Through this the appropriate reaction had to be determined out of the two possibilities. Through the use of a vacuum filtration system the mass of Cu was found to be 2.1726g which meant that through limiting reagent analysis Fe was determined to be the limiting reagent and the chemical reaction was determined to be as following:-

One milliliter of 6.00-M phosphoric acid was placed into a 125-mL Erlenmeyer flask using a volumetric pipette. Using a slightly larger pipette, six milliliters of 3.00-M sodium hydroxide was transferred into a 50-mL beaker. Then a disposable pipette was used to slowly mix the sodium hydroxide into the phosphoric acid while the solution was swirled around. Then both the beaker and flask were rinsed with 2-mL of deionized water and set aside. A clean and dry evaporating dish was weighed with watch glass on a scale. Then the solution was poured into the dish and the watch glass was placed on top. The solution was then heated with a Bunsen burner to allow for the water to boil off to reveal a dry white solid. After the dish cooled to room temperature it was once again weighed and the new mass was recorded.

Weigh out the necessary grams of Copper Sulfate Pentahydrate. The 40-degree group weighed out 40 grams. (See Figure 1)

0.5% of copper sulphate solution was added by drop at a time and and the test tube was shaked continuously.