swim, chem, baseball, I talk with my hands

Chemistry Honors – Class 17



  • Period B: Friday, September 26th
  • Periods D, G: Monday, September 29th

Exam Recap

  • General trends / observations about the exam
  • reminder about “bucket of points”
  • individual questions? see me during OH or other time

Lab Activity – Counting by Mass


  • Count out 25 pieces of an item and determine the mass
  • Grab a handful of the same item (without counting) and find its mass
  • Then count number of items in unknown sample
  • record important observations of each item
  • Repeat for as many materials as possible

Calculations (for each item)

  • Calculate the number of unknown items
  • Compare calculated number to the known, counted, number (percent error)
  • Calculate the mass of one dozen of each item.
  • Calculate the mass of one million of each item.
  • Determine how many of each would be needed to make 1.00 kg
  • Calculate the mass of 1 mole of each item (1 mole = 6.02 x 1023)
  • Determine the moles of each item that are equivalent to 543 pieces
  • Define mass. Discuss the difference between mass and weight.
  • Discuss the advantages of counting by mass as compared to counting manually


  • NO CROSS MULTIPLY – how do I show this? Units?
  • How do I show calculations in my LNB?
  • How many examples do I need to show?
  • What is a data table?
  • What is a calculation table?

Support Material

  • I have created a sample of what this lab could look like
  • Posted in the “Lab Work” section of the “Materials” part of the course Schoology site.
  • Please try and model your work after the posted document.


This entry was posted on 2014-09-25 by in Agenda, SHP-CH and tagged , , .


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