Journal Entry:
Arsenic, As, arsenic (III) oxide, As₂O₃, and arsenic (III) sulfide, As₂S₃, are all toxic because they contain arsenic.

1) Which is more toxic, 1 mol of As or 1 mol of As₂O₃? Explain your thinking.

2) Which is more toxic, 1 g of As₂O₃ or 1 g of As₂S₃? Explain.

Learning Intentions

• We will learn how to convert the number of moles of a compound or of an element to mass in grams.
• We will learn how to convert the mass of a toxic sample in grams to moles.

Closing Task:

You can use analyze data in a table with milligrams, grams and moles.

You can calculate number of moles based on number of grams of a sample.

Content Standards being covered:

Student understands what the letters and numbers stand for in a compound formula, can use those letter and numbers to determine how many of each type of element there are in a formula.

Student can create mathematical representations of chemical reactions and use them to make calculations about products and reactants.

Students can use mathematical representations to support the claim that atoms, and therefore mass, are conserved during a chemical reaction. (HS-PS1-7 and CCC Energy and Matter)