Lab 2: Separating a Mixture

LAB 2 – SEPARATING A MIXTURE – LAB REPORT CHM 2045L -Dr. Yavuz-Petrowski The statement is: “I certify that this is my own work and I understand that if I am found to be in violation of the honor code, I will be subject to the highest penalty” Name: Sofia Breton Znumber: Z23704642 PRELAB Background: Please complete the following sections. Purpose of the experiment: In your own words, the purpose of the experiment including a brief description of the lab and the reason for doing the experiment (what we are trying to determine and how we will go about determining it). Explain the concepts we are investigating; explain why and how they are useful, how those concepts apply to the experiment; show relevant equations if you need to. The purpose of this experiment is to apply separation techniques to isolate the individual components of a heterogenous mixture. In this lab, the goal is to identify and recover the sodium chloride (NaCl), calcium carbonate (CaCO3), and the silicon dioxide (SiO2) from a sample using a combination of physical and chemical methods. This involves filtration, evaporation, and chemical reactions to explore the differences in solubility and reactivity. The concepts of mixture versus compound, percent compositions, and percent errors are crucial to understand the effectiveness of the separations. This experiment reinforces how physical and chemical properties can be used to separate and analyze substances in a mixture, which is an important concept in chemistry and essential for applications in the real world. 3. Filter out SolidsWeigh and record the piece of filter paper. Filter the mixture to separate SiO2 and CaCo3. Record the mass of 100mL beaker. Collect the filtrate in the 100mL beaker and record the mass. Calculate and record the mass of NaCl.2. Initial Measurements and MixingRecord the mass of the clean beaker. Transfer the unknown mixture to an evaporating dish. Add 30mL of water to the dish and mix. Measure the mass of the beaker and mixture. Calculate and record the total mass of the unknown sample. Flow Chart: Complete experimental procedure for this experiment by using information provided in the power point and 360 experimental video in a flow diagram format. A flow chart indicates the procedure of how experiment is performed. The flow chart must be written in the correct flow chart format (box and arrow). Hand written flow charts are not accepted. See the example of the flow chart in canvas module. 1. Prepare EquipmentGather clean materials such as beakers, filter papers, and the chemicals needed. 4. Evaporate and Separate SubstancesHeat the solution to evaporate the water and recover NaCl. While heating, scrape remaining solids (SiO2 and CaCO3) from the filter paper. Add HCl to the solid mixture to dissolve CaCO3. Transfer final solution into a beaker. Record all masses. 6. Recover and Measure CaCO3Add NaCO3 to the CaCO3 solution to precipitate the CaCO3. Filter and dry the CaCO3 on the filter paper. Record the final mass of the CaCO3. 5. Isolate and Dry SiO2SiO2 still remains in the dish and can now be isolated. Dry the SiO2 on a hot plate. Record the final mass of the SiO2 8. Clean UpProperly dispose of waste, clean all lab equipment and pack up all materials. 7. Final CalculationsAdd the masses of SiO2, NaCl, and CaCO3 together. Compare it to the original sample mass. Calculate and record the percent error and percent compounds. Waste Collection: Type out the chemicals used in this experiment, and their hazards if applicable, and any other safety concerns associated with this experiment. You can search for the Materials Safety Data Sheet document on the internet to list hazards and safety concerns. You can add an extra row if you need extra space. Chemicals Safety Hazard Si02 (Silica) Can be hazardous if dust is inhaled, can cause skin irritation. Na2Cl3 Causes eye irritation, harmful if ingested. NaCl (Sodium Chloride) Causes eye irritation, can irritate open wounds, best to avoid skin contact. HCl (Hydrochloric Acid) Can irritate the eyes, skin, nose and throat. CaCo3 (Calcium Carbonate) Can irritate the eyes, or lungs if inhaled. TABLE: EXPERIMENTAL RESULTS YOU MUST SHOW ALL CALCULATIONS TO RECEIVE CREDIT FOR THEM. Proper use of significant figures and units is part of the grading. Handwritten calculations are not acceptable. If the student submits a handwritten calculation, the assignment will be graded with a 4-point deduction. MEASUREMENTS Mass of evaporating dish DATA, UNITS SHOW CALCULATIONS 42.163g 45.158g - 42.163g = 2.995g Mass of dish + unknown sample Mass of unknown sample 45.158g 2.995g Mass of 100mL beaker Mass of 100mL beaker + NaCl 66.120g 67.520g Mass of NaCl 1.4g 67.520g – 66.120g = 1.4g Mass of filter paper 1.187g 1.934g – 1.187g = 0.747g Mass of filter paper 1.934g + CaCO3 Mass of CaCO3 0.747g Mass of evaporating 42.854g dish + SiO2 42.854g – 42.163g = 0.691g Mass of SiO2 0.691g Total mass of sample recovered 2.837g 1.4gNaCl 0.69gSiO2 0.747gCaCO3 2.837g 49.34% 1.4gNaCl / 2.837 = 0.4934g x 100 = 49.34% 26.33% 0.747 / 2.837 0.2633 x 100 26.33% = = 26.43% 0.691 / 2.837 0.2435 x 100 24.35% = = % NaCl % CaCO3 % SiO2 + + = % error 5.275% 2.995 – 2.837 = 0.158 / 2.995 = 0.0527 x 100 = 5.275% CONSIDERATION FOR DISCUSSION & CONCLUSION As you write your discussion and conclusion paragraphs for the discussion assay, here are some tips and questions you should answer. These are in addition to the "Guidelines for a good discussion and conclusion" document in the introduction module. What are the differences between mixtures and compounds? Was your mixture homogenous or heterogenous? What physical and chemical methods are used to separate the mixture, and explain why each is either physical or chemical? According to the results, how much difference is the total mass of the sample recovered and the original mass of the unknown sample? Explain three places for possible experimental errors (human errors are not accepted as valid errors). Can the order of this experiment be changed, and can the components be separated in another way? Please explain in detail. In this experiment, I was able to successfully separate a heterogenous mixture composed of NaCl, CaCO3, and SiO2 using both physical and chemical methods. Mixtures are different from compounds because their components retain individual properties and can be separated physically, where compounds are chemically bonded and require chemical reactions to separate. The mixture used in this experiment was heterogenous, as its compounds were distinct and unevenly distributed. Physical separation methods used included filtration and evaporation, while the chemical separation technique involved the reaction of CaCO3 and HCl to form a soluble product, allowing separation. Based on the results, the recovered mass of 2.837g was slightly less than the original sample of 2.995g, showing a 5.275 percent error. Possible sources of error include the loss of material during transfer between containers, incomplete drying of filtered substances, and inaccurate mass measurements. Although the experiment followed a logical order, the steps could be rearranged. For example, filtering the solids before evaporating the NaCl solution could’ve increased recovery efficiency. The current order of steps for this experiment is best because it helps isolate the substances with minimal cross contamination. This experiment demonstrated the key principles of mixture separation and analysis.