Honors Chemistry Page 1 of 8

Honors Chemistry Page 1 of 8

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• Group IA metals (alkali metals)

1.1. Write the electron Configurations for the following elements:

1.2. Procedure: Go to the Open Learn Science website and make observations of the physical and chemical changes that occur during the demonstration

http://www.open.edu/openlearn/science-maths-technology/science/chemistry/alkali-metals

1.3. Observations:

1.4. Reaction Equations:

1.5. Based upon your review of the above website, what do you observe is the order of reactivity for each of the alkali metals?

1.6. What do you think might account for those differences-It’s an atom ‘thing’?

• Group IIA Metals (Alkaline Earth Metals)

pH and Conductivity

Preparation: Alkaline earth metal chlorides Testing Solutions:

A 50 ml solution of 0.1 M, Magnesium hydroxide solution Mg(OH)2

A 50 ml solution of 0.1 M, Calcium hydroxide solution Ca(OH)2

2.1. Before you conduct the next investigation, think about your first set of observation. Based upon what you observed, what do you hypothesize will be the differences between the pH and conductivity of IIA hydroxide solutions?

2.2.Test the pH and conductivity of each solution using the Vernier pH and conductivity probes

pH Conductivity

Mg(OH)2 ______

Ca(OH) ______

2.3.How would you compare your results to what you predicted about the pH and conductivity of IIA metal solutions?

2.4.What do you think might account for those differences?

• Solubility

Preparation: Alkaline earth metal chlorides Testing Solutions:

1. Barium chloride solution, 0.1 M, BaCl2,
2. Ammonium oxalate solution, 0.25 M, (NH4)2C2O4
3. Calcium chloride solution, 0.1 M, CaCl2
4. Potassium iodate solution, 0.2 M, KIO3
5. Magnesium chloride solution, 0.1 M, MgCl2
6. Sodium carbonate solution, 1 M, Na2CO3
7. Strontium chloride solution, 0.1 M, SrCl2
8. Sodium sulfate solution, 1 M, Na2SO4

1. Add several (approximately 5) drops of an alkaline earth metal chloride solution to each well in a horizontal row, as follows (see Figure 1):

• magnesium chloride to wells A1–A5

• calcium chloride to wells B1–B5

• strontium chloride to wells C1–C5

• barium chloride to wells D1–D5

1. Add several drops of testing solution to each well in a vertical column, as follows (see Figure 1):

• potassium iodate to wells A1–D1

• sodium sulfate to wells A2–D2

• ammonium oxalate to wells A3–D3

• sodium carbonate to wells A4–D4

1. Record results on the following table. If a solid appears, record as ‘ppt’ in the circle.

3.1. Based upon your observations, where the any patterns that emerged between the elements.

3.2. What do you think might account for those differences?

• Group VIIA Nonmetals (The halogens):

4.1.First, compare the visible physical properties of the three elements Cl2, Br2, and I2, which are displayed in bottles on the side shelf. Be sure to notice the colored vapors above the liquid and solid.

Element Physical State Color

Cl2 ______

Br2 ______

I2 ______

4.2.Which of these three elements is most volatile (most easily vaporized)? ______

4.3. How does the volatility of the elements vary with the atomic mass of the Cl2, Br2, and I2 molecules?

4.4.In 50 ml beakers, measure the conductivity of the aqueous solutions of the 0.1 M sodium halides using the conductivity probe (use the 0-20,000 toggle setting).

Solution Conductivity

20 ml. NaCl(aq)______

20ml NaBr(aq)______

20 ml. NaI(aq)______

5.2. Based upon your observations, where there any patterns that emerged between the VIIA elements.

5.3. What do you think might account for those differences?

• Solubility

5.1. Preparation of Solutions:

1. Chlorine Water: To prepare 100 mL of chlorine water, mix 13 mL of 5% sodium hypochlorite solution (bleach) with 30 mL of 1 M hydrochloric acid. Dilute to 100 mL with distilled water and stir to mix. Store in a labeled glass bottle or stoppered flask until needed. Work with chlorine water in the hood.

1. Bromine Water: To prepare 100 mL of bromine water, mix 30 mL of 1 M sodium bromide solution with 30 mL of 1 M hydrochloric acid. Add 15 mL of 5% sodium hypochlorite solution (bleach) followed by 25 mL of distilled water and stir well to mix. Store in a labeled glass bottle or stoppered flask until needed. Work with bromine water in the hood.

1. Iodine Solution: ______

5.1. Procedure

1. Label six square glass bottles 1–6

1. Using a graduated cylinder, measure and add 5 mL of chlorine water to each bottle 1 and 2. Cap the bottles.

1. Draw a line to mark the level of liquid in bottles 1 and 2, and mark off a line at the same height in each bottle 3–6.

1. Add bromine water to the 5-mL line in each bottle 3 and 4.

1. Add iodine solution to the 5-mL line in each bottle 5 and 6.

1. Record the color of each aqueous halogen solution in Data Table A.

1. Using a clean graduated cylinder, measure and add approximately 10 mL of hexane to each test tube 1–6.

1. Place a stopper in each test tube and carefully invert each tube several times to mix the liquids. There should be two layers—the top organic layer (hexane), and the bottom aqueous layer (water).

1. For each aqueous halogen/hexane mixture, record the colors of the upper and lower liquid layers in Data Table A.

1. Add 5 mL of sodium bromide solution to the chlorine mixture in bottle 1. Cap the bottle and carefully invert several times to mix the liquids. Observe any reaction that occurs—look for changes in color to either layer. Record all observations in Data Table B. If no change is apparent, write no reaction (NR) in the data table.

1. Using the information in the following chart, repeat step 10 for all of the possible halogen–sodium halide combinations in bottles 2–6.

1. Record detailed observations as each solution is added. Complete Data Table B.

5.2. Based upon your observations, where there any patterns that emerged between the VIIA elements.

5.3. What do you think might account for those differences?