Now add ~ 0.35 g of zinc powder to the solution and stir until the solution becomes clear. Dissolve the excess zinc with more sulfuric acid. Decant the liquid with a stirring rod, retaining only the copper. Rinse the copper with distilled water and steam dry. Weigh the mass.
• It is usually a pink coloured liquid based on an acid solution of a compound into which the articles are immersed completely for removal of tarnish. • The silver should remain in the liquid for a very short time, the articles should be lifted out, washed with warm water and dried. • While working with silver dip, stainless steel containers should not be used since the dip attacks
The objective for the second part is to compute for the percent composition of the potassium chlorate in a mixture correctly. Stoichiometry is the branch of chemistry and chemical engineering that deals with the quantities of substances that enter into, and are produced by, chemical reactions. It is the accounting, or math behind, behind chemistry. Given adequate information, Stoichiometry can be used to calculate masses, moles, and percents within a chemical equation. Methodology A test tube containing 0.2 gram of manganese dioxide was weighed.
Remove stopper and test for the gas that evolved by holding a lighted taper to the mouth of the test tube. Repeat using zinc sample. Repeat using copper sample. Repeat using iron sample. (b) REACTION WITH METAL OXIDES Place a very small amount (the size of a few grains of rice) or copper (II) oxide in a test tube and add about 2mL of hydrochloric acid.
Recording the data collected at specific temperatures was a major part of the experiment to perform calculations to determine the enthalpy and entropy. To improve the data, limit any chances of losing the borax after weighing by transferring it into the beaker at the balance station. Adding less indicator could also help with recognizing the end point and lessen the chances of getting a yellowish solution. Once the end-point is almost reached, we should add one drop at a time and swirl it to check for color change. Allowing the borax solution to boil longer to reach a higher temperature would allow the solid to dissolve; which would lessen the change of any particles being transferred into the aliquot.
Add decolorizing carbon to remove the colored impurities. -Hot Filtration – this separates the insoluble impurities from the soluble pure compound by pouring the solution through a hot filtration apparatus (filter). -Formation (Recrystallization) – allows the hot solution to cool and begin to form crystals. For rapid cooling, an ice water bath can be used. -Isolation – Using a vacuum filtration, the excess solvent will be removed from the crystals.
Then add 1mL of deionized water. Tap the end of the test tube to mix the solution and record the pertinent data in section 2 of the Data Table. Discard the solution in the appropriate container as directed to you by your lab instructor. 3. Put a sample of zinc into a test tube.
Preliminary experiment Limewater and copper carbonate were used to see if a metal carbonate beaks down to produce carbon dioxide. This is what the experiment looked like: The equation for this: CaCo3(s) CuO(s) + Co2 (g) This experiment was to see if carbon dioxide was produced from a metal carbonate. In this case copper carbonate was used. Two test tubes were linked together by a rubber tube, which had a glass pipe coming out of the cork that prevented any of the carbon dioxide or any other gas from escaping. As you can see from the diagram in one tube there was limewater that was to test for the carbon dioxide, and in the other was copper carbonate.
Plan After making sure everything is safe, I will first start the experiment with zinc. I will measure out 25 cm3 of CuSO4 in a measuring tube. Then I will put it into a polystyrene cup with the lid. I will insert a thermometer through the lid of the cup until it touches the liquid. Then I will take one spatula of zinc.
The two solids we tested in this experiment were NaCl (Sodium Chloride) and NaNO3 (Sodium Nitrate). To begin the experiment, we measured 5cc of water and 5g of NaCl and added them to a test tube. Next, we stoppered the test tube and shook vigorously for two or three minutes. After we observed that the solution was saturated and massed an evaporating dish (18.89g) and poured most of the solution into it, while being careful not to pour any undissolved solid into the dish. Next, we massed the evaporating dish with the solution and found it to be 23.32g.