Chemistry Honors – Class 17

Dates

• 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

Data

• 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

Coaching

• 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.