1 / 35

You need your lab notebook!!

You need your lab notebook!!. A note on assignments. Late homework is worth 50%. I will not stamp the date on it. BE ORGANIZED!! Keep your notebooks in one place (on your shelf). Keep a separate notebook for each class.

vilmos
Télécharger la présentation

You need your lab notebook!!

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. You need your lab notebook!!

  2. A note on assignments • Late homework is worth 50%. I will not stamp the date on it. • BE ORGANIZED!! Keep your notebooks in one place (on your shelf). • Keep a separate notebook for each class. • You are in 10th grade. It is YOUR responsibility to complete assignments on time and to not lose your things.

  3. Studying • Flashcards • Self quiz • Quiz a friend • Teach a friend from memory • Draw and label diagrams from memory • Rewrite notes • Make up practice quiz questions

  4. Retaking a quiz • Tuesday 8:10-9:00 pm • Thursday 7:00-8:00 pm • Call from desk, 2nd floor: 814 • I will give you the higher mark

  5. Separation of a Mixture 16 Oct. 08 • Objectives: 1. • 2. • Techniques: 1. • 2. • Materials • (skip 5 lines) • Procedure: Observations: • Find the mass…

  6. Separation of a mixture

  7. Objective • To separate a mixture of manganese dioxide and sodium chloride. • To determine the percent of each obtained after the separation, and the percent error.

  8. Compounds • manganese dioxide, MnO2, insoluble black powder (manganese (IV) oxide) • sodium chloride, NaCl, soluble white crystals

  9. Technique • Filtration • Evaporation

  10. Filter paper funnel

  11. Desiccator (removes water from a sample) Stirring rod

  12. Weighing paper Drying oven (removes water from a sample quickly)

  13. beaker

  14. Alcohol burner Ring stand/ring

  15. Spatula (for moving powdered chemicals from their containers) Evaporating dish

  16. Procedure • Find the mass of the 100 mL beaker on the electronic balance. • Mass 2 grams of NaCl and 1 gram of MnO2 on weighing paper, and record their initial masses. Mix them together in the beaker. • Add 20 mL distilled water to the NaCl and MnO2 mixture. Swirl gently to mix, until all the NaCl is dissolved. Record a qualitative description. How would you separate this mixture (and record the mass of each compound after separation)?

  17. Equipment • Beakers(2, 100 mL), electronic balance (1), distilled water, graduated cylinder (1, 100 mL) • NaCl (powder, 2g), MnO2 (powder, 1 g)

  18. Homework 1 • Draw a cartoon of the SIX main steps required to separate this mixture, • and to find out the mass of each compound collected at the end. • Write a sentence to describe each of the six steps, under each box of the cartoon. • Due: Fri.

  19. Goals: Separate the manganese dioxide from the NaCl. • Find the mass of each compound after the separation, and compare it to your initial masses. • Calculate your percent error.

  20. Homework • Due Thursday (with your cartoon) • On a separate piece of paper: • Write the procedure for separating these two compounds (don’t worry about collecting the water)and calculating % obtained/%error. • Write a list of materials and equipment required (include how many of each).

  21. A good procedure… • Very specific – list every detail even if you think it is obvious! • In the correct order • Give the name of each piece of equipment you use • Write when you will make observations or take a measurement • Describe how to do each calculation

  22. If you do not turn in this assignment, you will not be allowed to participate in lab. • We will edit your procedures before going to lab. • Do your best…draw pictures if you have a hard time writing sentences. • Come see me for help!

  23. Process of Separation Mixture Suspension Filtration Residue – manganese dioxide Solution Reacts with HCl acid, turns moist KI paper blue Evaporation Solute – sodium chloride Water Reacts with AgNO3 solution to form white precipitate

  24. Qualitative Observations:

  25. Common Challenges Add to your procedure to fix these problems!!

  26. When filtering • How will you keep salt water from being absorbed by your filter paper?

  27. Wet the filter paper with distilled water from the wash bottle before filtering.

  28. When evaporating • How will you know when all the water is evaporated?

  29. When the salt looks dry, mass the dish + salt. Heat it a little longer, and mass it again. Repeat, until the difference in mass is less than 0.01 grams.

  30. When finding final mass • Scraping the NaCl from the evaporating dish and the MnO2 from the filter paper onto weighing paper will cause you to lose a LOT of mass. How can you avoid this?

  31. Mass the filter paper and evaporating dish at the beginning. At the end, mass the filter paper + MnO2 and the evaporating dish + NaCl. Then, just subtract!!

  32. Calculations • The procedure MUST show how to find the final mass of NaCl and MnO2. • Also describe how to calculate % obtained (the percent of each at the end), and % error.

  33. Homework • Write a final draft of your procedure in your lab notebook (in the left column). • Under “Materials,” list all the pieces of equipment and compounds, including how many/how much of each. • Due Thursday, 30 October, in lab • No procedure = no lab

More Related