Experiment 6 - Chemical Periodicity

1

• Experiment 6 - Chemical Periodicity
• Record these Safeties into your notes
• lithium metal, sodium metal and potassium metal
  all react violently with water and may catch
  fire. These are reducing agents. Work with these
  under the fume hood. Use a wire screen over the
  top of your beaker to prevent flaming material
  from escaping in the reaction of alkali metals
  and water.
• Li(s), Na(s), K(s) in water produce alkali
  hydroxides solutions (NaOH is lye) which are
  strongly basic and can burn you (see Fight Club
  and wear your safety goggles) . Dont get these
  on you. Rinse with water if you do.
• Chlorine water, bromine water and iodine water
  are oxidizing reagents will oxidize your skin
  destroying skin tissue to cause a burn. Dont get
  these on you. Rinse with water if you do.
• MgO, CaO (lime or quicklime), BaO are called
  basic oxides because mixed with water produce
  hydoxides which an can burn you (see Fight
  Club) . Dont get these on you. Rinse with
  water if you do.

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Part A
- Complete before coming to class
test for in lab
Please answer
3
Part B
- Complete before coming to class
Add to notes
Please answer
4
Part C
- Complete before coming to class
When doing this reaction, 1)do under the fume
hood, 2) cover beaker with wire screen
Safety First!
give all reactions for Li,Na,K
Add the missing reactions for Li and K in water
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• Part D - Seven Diatomics H2(g) N2(g) O2(g) F2(g)
  Cl2(g) Br2(l) I2(s)
• X2 (gaining and retaining electrons)
• All X2, especially halogens have a significant
  affinity to gain retain electrons. In the
  reaction, we will compare Cl2 versus Br2 versus
  I2
• X2 likes to gain electrons or get reduced
  reduction is the chemical electron transfer
  process for gaining electrons.
• Halogens, X2, with the greatest affinity to gain
  electrons will lose their color and will emerge
  in an anionic form as MX in the reaction.
• A more reactive winner between competing
  halogens in the reaction will lose their color
  will appear colorless in aqueous solution.
• If a colored halogen Y2 is present in the oil
  layer it is the less reactive loser halogen in
  the reaction. If, X2, a colored halogen is
  present in the oil layer it is the less reactive
  halogen the reverse reaction below is preferred.

6
cork shake like mad!
Add to table
color in oil the competitors
brown
purple
yes

• Procedures
• Prepare six test tubes in a rack.
• Add 1-cm of mineral oil to each test-tube.
• Add 10-drops bromine water into two test tubes,
  cork shake vigorously.
• Add 10-drops chlorine water into two test tubes,
  cork shake vigorously.
• Add 10-drops iodine water into two tests tubes,
  cork shake vigorously.
• Record the initial color of all six test tubes in
  the table above.
• Then combine 1-cm of the corresponding solutions
  (NaCl, NaBr, NaI) to each test tube as indicated
  above.
• Cork tightly and shake each vigorously for 5
  minutes.
• Record your final color observations in the
  table above. The halogen color that remains in
  the oil layer is LESS reactive

Add to notes