Lab 1 - Identification of Metals - Lab Report

Lab 1 – Identification of Metals – 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 PART I: 360 SIMULATION Table 1. Determining the Densities. Please complete data table by using 360 virtual lab simulation. Only observations based on the 360 video results will be accepted as correct answer. Be sure to record your measurements with the appropriate number of significant figures. You must show all your calculations to receive credit for them. You must type your answers for each section. Handwritten reports will not be accepted or will be graded with 4 points deduction. By using simulation, record: Mass of the unknown metal sample Volume of the unknown metal Complete Density calculation of the unknown metal Plot excel graph to find the density Calculate a verage density Data Points Collected Mass of weighing dish, g Unknown Metal Unknown Metal Unknown Metal Unknown Metal #1 #2 #3 #4 2.027g 2.019g 2.119g 1.953g Mass of weighing dish and unknown metal sample, g 4.524g 5.743g 9.821g 13.947g 2.497g 3.724g 7.702g 11.994g Volume of water, mL 5.00mL 5.00mL 5.00mL 5.00mL Volume of water and metal, mL 5.32mL 5.48mL 6.00mL 6.6mL Volume of unknown metal sample, mL .32mL .48mL 1.00mL 1.6mL Density of metal sample, g/mL 7.80 7.76 7.70 7.50 Mass of unknown metal sample, g Average density value from calculation (g/mL) 7.69 Density value from excel graph (g/mL) 7.57g Identify of Metal Tin Calculations: YOU MUST SHOW ALL CALCULATIONS TO RECEIVE CREDIT FOR THEM! Calculations needs to be typed Proper use of significant figures and units is part of the grading. Trial 1: Unknown Metal #1 Mass of metal sample = 4.524 g - 2.027 g = 2.497 g Volume displaced = 5.32 mL - 5.00 mL = 0.32 mL Density = 2.497 g / 0.32 mL = 7.80 g/mL Trial 2: Unknown Metal #2 Mass of metal sample = 5.743 g - 2.019 g = 3.724 g Volume displaced = 5.48 mL - 5.00 mL = 0.48 mL Density = 3.724 g / 0.48 mL = 7.76 g/mL Trial 3: Unknown Metal #3 Mass of metal sample = 9.821 g - 2.119 g = 7.702 g Volume displaced = 6.00 mL - 5.00 mL = 1.00 mL Density = 7.702 g / 1.00 mL = 7.70 g/mL Trial 4: Unknown Metal #4 Mass of metal sample = 13.947 g - 1.953 g = 11.994 g Volume displaced = 6.00 mL - 5.00 mL = 1.00 mL Density = 11.994 g / 1.00 mL = 7.50 g/mL Average Density = (7.80 + 7.76 + 7.70 + 7.50) / 4 = 7.69 g/mL 360 Lab Graph Excel Graph : Edit your graph so that it contains the correct formatting components – you need a descriptive title and labels for your x- and y-axes (don’t forget units!). Add screenshot s of your Excel graph. Make sure the graph is correctly formatted and labeled . If you are on a Windows device, hold down ( Windows key )+( shift ), then press ( s ). Use your mouse to draw a rectangle around your graph, then ( ctrl )+( v ) below to paste the image. If you are on a Mac, hold down ( cmd )+( shift ), then press ( 4 ). Use your mouse to draw a rectangle around your graph. The image should be saved as a file on your desktop. Click and drag it below to paste it into the document. PART II: Mark type of graduated cylinder used and type of unknown metal. Graduated Cylinder Used: Unknown Metal: Table 1. Determining the Densities: Fill out the following table with your collected data. Your table should have 5 data entries for selected unknown metal. Be sure to record your measurements with the appropriate number of significant figures. Unknown Metal Unknown Metal Unknown Metal Unknown Metal Unknown Metal #1 #1 #1 #1 #1 Mass of weighing dish, g 4.9300g 5.2646g 5.4118g 5.8103g 17.8446g Mass of weighing dish and unknown metal sample, g 9.9300g 20.2646g 25.4118g 12.8103g 36.8446g Mass of unknown metal sample, g 5.00g 15.00g 20.00g 7.00g 19.00g Volume of water, mL 5.00mL 5.00mL 5.00mL 5.00mL 5.00mL Volume of water and metal, mL 8.7353mL 20.2766mL 23.7327mL 12.0259mL 25.7444mL Data Points Collected Average density value from calculation, g/mL 1.083g/mL 0.8932g/mL Density value from excel graph Aluminum Identity of metal CALCULATIONS/WORK: CALCULATIONS: YOU MUST SHOW ALL CALCULATIONS TO RECEIVE CREDIT FOR THEM! CALCULATIONS NEEDS TO BE TYPED. PROPER USE OF SIGNIFICANT FIGURES AND UNITS IS PART OF THE GRADING. Trial 1 Mass of metal = 9.9300 g - 4.9300 g = 5.0000 g Volume displaced = 8.7353 mL - 5.0000 mL = 3.7353 mL Density = 5.0000 g / 3.7353 mL = 1.338 g/mL Trial 2 Mass of metal = 20.2646 g - 5.2646 g = 15.0000 g Volume displaced = 20.2766 mL - 5.0000 mL = 15.2766 mL Density = 15.0000 g / 15.2766 mL = 0.982 g/mL Trial 3 Mass of metal = 25.4118 g - 5.4118 g = 20.0000 g Volume displaced = 23.7327 mL - 5.0000 mL = 18.7327 mL Density = 20.0000 g / 18.7327 mL = 1.068 g/mL Trial 4 Mass of metal = 13.6262 g - 5.8103 g = 7.8159 g Volume displaced = 12.0259 mL - 5.0000 mL = 7.0259 mL Density = 7.8159 g / 7.0259 mL = 1.113 g/mL Trial 5 Mass of metal = 36.8446 g - 17.8446 g = 19.0000 g Volume displaced = 25.7444 mL - 5.0000 mL = 20.7444 mL Density = 19.0000 g / 20.7444 mL = 0.916 g/mL Average Density = (1.338 + 0.982 + 1.068 + 1.113 + 0.916) / 5 = 1.083 g/mL Chemcollective Graph Excel Graph : Edit your graph so that it contains the correct formatting components – you need a descriptive title and labels for your x- and y-axes (don’t forget units!). Add screenshot s of your Excel graph. Make sure the graph is correctly formatted and labeled . PART III: COLLECTING INFORMATION USING THE “PERIODIC TABLE LIVE!” SOFTWARE Using the software collect the following information about the metals. METAL DENSITY COPPER 8.96 SILVER 10.49 ALUMINUM 2.70 PLATINUM 21.45 ZINC 7.14 RHODIUM 12.41 TIN 7.31 DIFFERENCE 1.62 0.38 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. Which way turned out to be the most accurate to determine the density of the metal, calculation from a single data point, slope of the manually drawn or the computer-created graph? What do you think and why? Is there another way you could determine the volume of the cylinder other than the volume displacement of water? If so, describe how you would do it. How close was your calculated density to the actual value? Discuss why your density may not match this value. If you had used a different amount of an unknown metal, would the density you obtained be the same or different? DISCUSSION & CONCLUSION ASSAY I think that the most accurate method for determining the density of the metal was using the slope of the computer created graph. I think that by using the computer graph it helped eliminate little errors that could occur in individual trials making a more reliable and consistent density value. A different way to determine the volume of the metal sample, not counting the water displacement, would be using a caliper to measure its dimensions and then to apply the appropriate volume formula. My calculated densities were close to the actual values, for example the calculated density for tin was 7.69 g/mL, only 0.38 g/mL off from the true value. Some differences showed up in measurement inaccuracies, air bubbles during water displacement, or even simple reading errors. If a different amount of the same unknown metal were used, the density should theoretically remain the same since density is an intensive property and does not depend on the quantity of the substance. This lab helped me better understand the importance of precision, multiple trials, and graphical analysis in experimentally determining properties like density.