Alchemy Unit

1
Alchemy Unit

• Investigation II
• Lesson 1
• A New Language

2
ChemCatalyst

1. There are two bottles on a shelf in a chemistry
   lab. Both contain a shiny metal substance that
   resembles gold. Bottle A is labeled Au (s).
   Bottle B is labeled FeS2 (s).
2. Do you think both bottles contain gold? Why/why
   not?
3. What elements are Au, Fe and S?

3
Discussion Questions

• What does the number 2 in the formula FeS2 mean?
• Why are some letters capitalized and some not
  capitalized?
• Can you define the word element?
• How are elements different from compounds?

4
A New Language Instructions

• What do the chemical symbols tell us about the
  substance inside the vial?
• You will make careful observations of the
  substances in the 17 vials.
• Then, you will identify an unknown substance in
  vial 18.
• DO NOT OPEN THE VIALS!!!!

5
Making Sense Discussion

• Chemical formulas tell us which elements a
  substance contains.
• What symbols are used to label something called
  a
• Sulfate
• Nitrate
• Hydroxide
• What symbols represent copper sulfate?

6
Making Sense Discussion

• Is copper sulfate an element or a compound?
• What elements are in copper sulfate
• What do the subscript numbers mean?

CuSO4
7
Definitions

• A chemical formula is the set of symbols a
  chemist uses to represent a compound.
• A compound is a substance that consists of two or
  more elements chemically combined

8
What About Letters in ( )?

• What do (g), (l) and (s) mean?
• What is
• H2O (l)
• H2O (g)
• H2O (s)

9
What About (aq)?

• What do all the flasks with (aq) on them have in
  common?
• Aq stands for aqueous? a substance is dissolved
  in water
• How are NaOH (s) and NaOH (aq) the same? How are
  they different?
• How are NaOH (aq) and H2O (l) the same? How are
  they different?

10
More About Aqueous Solutions

• Solute substance dissolved in the water
• Solvent the water
• So a substance is aqueous if it is dissolved in
  water

11
Check In

• Imagine that you find a flask that is labeled
  Na2SO4 (aq)
• What does the label tell you about what is in the
  flask?

12
Youre Ready for a Quiz

• Tomorrow!

13
Quiz

1. Name the elements in the formula for sodium
   nitrate, NaNO3
2. Whats the difference between CuSO4 (s) and CuSO4
   (aq)?
3. If salt, NaCl (s) is dissolved in water, H2O (l),
   how would you write the chemical formula for the
   resulting salt water solution?

14
Quiz

• 4. If sugar, C6H12O6 (s) is dissolved in water,
  H2O (l), how would you write the chemical formula
  for the resulting sugar water solution?
• 5. What is the solvent and what is the solute in
  a salt water solution?