Lab 8 Procedure

The three steps of the lab are:

  1. Perform 10 reactions and record observations.

  2. Balance 10 reaction equations.

  3. Classify the 10 reactions based on observations of the reactions and pattern recognition within the reaction equations.

Safety for this lab:

  • Wear safety glasses at all times.

  • Perform all burning and heating in the fume hood.

  • ALWAYS clean up your entire station and any spills made at shared stations.

  • DO NOT deposit broken glassware in trash, place into broken glassware container located near paper towels.

Reaction 1:

Gently heat a medium test tube containing a small amount copper(II) hydroxide with a bunsen burner.  For safety, always have the mouth of the test tube directed away from you.  Heat until you observe water vapor forming on the inside of the test tube. 

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Dispose into copper waste container.

Reaction 2:

Using a disposable pipet, place 3% hydrogen peroxide into an evaporating dish (1/4 to 1/2 full into evaporating dish).  Place the evaporating dish under the fume hood, near the front edge.

Obtain a small scoop of sodium iodide and have it ready to pour into the hydrogen peroxide.

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Light a wood stick under the fume hood near the evaporating dish.

When wood stick has a flame, quickly pour the sodium iodide into the hydrogen peroxide.

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Hold the burning wood stick over the hydrogen peroxide while the gas is being released.  Observe what happens to the flame/glowing ember on the wood stick (does the gas feed the flame? Does the gas cause the flame to pop?  Does the gas put the flame out?).

Discard liquids safely into the sink and solids in the garbage.

Reaction 3:

Using two separate disposable pipets, mix equal amounts of copper (II) chloride solution with sodium phosphate solution into a well plate. Observe the color of the solid formed.

l08_14 L08_15.jpg This is a well plate

Dispose into copper waste container.

Reaction 4:

Using the same technique as described for Reaction 3, mix calcium chloride solution with sodium carbonate solution. Observe the color of the solid formed.

l08_17 l08_15 This is a well plate

Discard liquids safely into the sink.

Reaction 5:

Using a disposable pipet, place 3 mL of 1M hydrochloric acid into an evaporating dish (1/4 to 1/2 full into evaporating dish).  Place the evaporating dish under the fume hood, near the front edge.

l08_16 This is an evaporating dish

Using a scoopula obtain a small scoop of magnesium.

Light a wood stick under the fume hood near the evaporating dish.

When wood stick has a flame, quickly pour the magnesium into the hydrochloric acid.

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Hold the burning wood stick over the hydrochloric acid while the gas is being released. Observe what happens to the flame/glowing ember on the wood stick (does the gas feed the flame? Does the gas cause the flame to pop? Does the gas put the flame out?).

The data sheet will show two reactions. The first reaction is when you added the magnesium to the hydrochloric acid. The second reaction is when you ignite the hydrogen with oxygen with the lighted wood.

Dispose into magnesium waste container.

Reaction 6:

Add a small piece of zinc foil into a well plate or watch glass.  Using a disposable pipet, add enough of the copper sulfate solution to cover the zinc foil. Observe the color change.

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Dispose into copper waste container.

Reaction 7:

Using a disposable pipet, place sulfuric acid solution into a test tube (1/4 to 1/2 full into test tube). Record the temperature.

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Using a disposable pipet, add approximately the same amount of sodium hydroxide solution to the same test tube.

Record the new temperature and note the change in temperature.

Discard liquids safely into the sink.

Reaction 8:

Using your lighted Bunsen burner hold a piece of magnesium using tongs over the flame until lit.  Allow to burn in the fume hood (do not look directly at the light).

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Dispose into magnesium waste container.

Reaction 9

Perform the following in the fume hood.

Fill a large test tube about half-filled with water. Now do not hold the test tube with your hands so place inside a large beaker, making sure the opening of the large test tube is pointing away from you.

Add a few drops of phenolphthalein (it’s in the small dropper bottle) to the water inside the large test tube.

 

Using tweezers, obtain 1 or 2 pieces of calcium and place inside the water and observe the gas being released and color change.

Dispose into calcium hydroxide waste container.

Reaction 10

Soak a mole dollar bill in a solution that is 50% water / 50% isopropyl alcohol.

Using the crucible tongs to hold a mole dollar, gently ignite the dollar inside the fume hood. Once it’s lit move it away from the Bunsen burner and allow it to burn. If done right, you should still have your mole dollar (this is the burning money trick).

Return the mole dollar bill to allow to dry.

FINAL STEP: CLEAN YOUR STATION 

Use the sinks and soap to wash your glassware. 

PUT AWAY ALL EQUIPMENT AND CHEMICALS AND WIPE DOWN YOUR STATION.

Do not leave the lab until the instructor has inspected your clean station.