Iron Decomposition

1
Iron Decomposition
2
Goals

• To determine the ______________________
• ________________________________
• To _______________ based on these results
• Determine whether __________________
• _________________________________________
• Comparison to theoretical H2O in the hydrate
• Observation of litmus during heating
• To determine whether a _________________
• ______________ occurs by comparing reactions with
  varying oxidation states

3
Disposal

• Iron
• Barium KSCN
• KMnO4
• HCl

4
Part 2

• Just like H2O experiment in CHM161
• Used to determine whether just water is driven
  off (
• or something more
• Last time, you determined how much water was lost
• This week _________________________________
• So, we determine the ________________________
• ____________________, not necessarily the H2O
  lost
• We compare the ______________to the H2O in the
  salt hydrate to determine if something more was
  lost

5
Part 2 Calculations

• H2O in salt hydrate
• Experimental ?
• Note that mreag mprod mlost as gas

6
Are H2O and ? the same?

7
Litmus Tests

• What is Litmus Paper?
• Blue turns
• Red turns
• Wet the litmus before sticking it in the vapors
• Will the water affect the tests?

8
Litmus Results

• What can these tests tell us?
• If being in the vapors changes either litmus,
  ______________________________________
• ______________________________________
• If being in the vapors does nothing, __________
• _________________________________________
• Check multiple times. Why?

9
Parts 1 3

• Part __ is done to compare part __ to
• Part __ tests the product from part __ to test
  hypothesis _________________________
• Try to decide if the part __ tests result in the
  same changes that you saw for Fe2 or Fe3 in
  part __
• Use the same type of logic as for part __ to base
  your decisions
• In order to do this, must understand experimental
  controls

10
Experimental Controls

• What is a control?
• Why do you need them?
• What types of controls should you have when you
  do an experiment?

11
Positive Control

• Many types
• Acts as a

• catechol water apple juice
• Standard solutions with known concentrations

12
Negative Control

• Produces _________ that is a result of the
  _______
• _______________________
• Can indicate __________
• _______________________
• _______________________
• Can indicate

• catechol water
• Using water to zero a spec
• Titrating water as a blank (ie Ca-EDTA)

13
Todays Controls (parts 1 3)

• 1a control for
• 1b control for
• 1c control for
• 1d control for
• 1e control for
• 1f control for