Study pool doesn't have the ability to download more than 4 objects so you will find 4 labs in one word file and the others pdf. If you have problem with any of the labs tell me and I will send the lab alone. You have the choice between write on it by computer or print it. If you need anything else please let me know.
Here is youtube links you will need in Lab 04 (Determining the Empirical Formula of a Hydrate):Bellevue College | CHEM& 161 NAME_________________________ SECTION_____ Pre-Lab Assignment—To be completed BEFORE lab! Read the background section of this experiment. Answer the following questions. 1) A student performed an analysis of a sample for its calcium content and obtained the following results: 14.92 g, 14.91 g, 14.88 g, 14.92 g The actual amount of calcium in the sample is 20.90 g. For this lab, the instructor asked students to obtain results within 5% error and RSD and to redo the experiment if that was not achieved. (a) Report the student’s results for the average and the standard deviation of the measured masses. Show your calculations below. Do the calculations by hand, and if you have a calculator or Excel you can use it to check your answer. _________g ± ______g (average) (standard deviation) (b) Calculate the percent error, using the average mass, for this student’s experiment. (c) Calculate the relative standard deviation for this student’s experiment. (d) Briefly comment on the accuracy vs. the precision obtained by the student. Does the student need to redo the experiment? Page 13 of 14 Bellevue College | CHEM& 161 2) (a) Provide a measurement for each of the following pieces of glassware filled to the level indicated by the arrow. Use the correct number of significant figures in your answer. Always use units. Remember to estimate one digit more than the level of graduation. mL mL 10 mL 11 ________ ________ (See note below*) ________ *Volumes in burets are read from top to bottom. (b) Which gives the most precision, (a.) the graduated cylinder, (b.) the buret, or (c.) the beaker? (c) How can you tell by simply looking at the glassware? Explain briefly. 3) (a) Label this beaker with values so that it can report volume to the tens (not tenths) place. (“Report to” means to record digits to this decimal place, including your estimated digit.) (b) Give a sample measurement that could be obtained from this beaker. Use mL for units. Use significant figures. Page 14 of 14 Density Assignment Purpose • • • To observe how objects can displace water. To determine the density of solid objects by the water displacement method. To investigate density as a ratio. • To identify an unknown material. Tasks 1. Watch this video and note: (a) the difference between the terms mass, volume, and density, (b) How the volume of objects can be measured by water displacement. https://www.youtube.com/watch?v=GnBQ6vIutDM (Links to an external site.) 2. Navigate to the Density Simulation (Links to an external site.) hosted online by PBS station KCTS9. Click on the Play Arrow (on the picture) to start the simulation. (full link: https://kcts9.pbslearningmedia.org/resource/arct15-sci-densitylab/density-lab/ (Links to an external site.) ) 3. Down load, print and perform the experiment according to the instructions in the Lab Report Sheets file attached to this Module. 4. Submit your Lab Report Sheets as a single PDF file to this assignment page here in Canvas. CHEM& 140 Density Lab Name: ____________________________________ Report Sheets: Density Lab Instructions: It will help your instructor if you choose a different color to write in your answers. Thank you so much! Pre-lab Questions 1. Define the following terms in your own words (1.25 pt) a. Physical Property b. Chemical Property c. Extensive property d. Intensive property e. Density 2. Write the equation used to calculate density. (0.25pt) 3. What are common units for density (in the metric system) for each of the following: (0.25 pt) a. Solids b. Liquids c. Gases Part 1: Sink vs. Float Click the “Turn Fluid into Water” button. (If at any time, you move the fluid density slider next to the container,