1-5 Types of Chemical Reactions stations lab fy11

[Pages:4]CP Chemistry

Theodore Roosevelt High School

Types of Chemical Reactions Lab

Introduction During any chemical reaction, the Law of Conservation of Matter must be satisfied, meaning that there must be the same kind and number of atoms on each side of the chemical equation. Recognizing and using categories of reactions can make determining the reactants and products much easier. The five general types of reactions that you will study in this lab activity are: combination, decomposition, combustion (or burning), single replacement (or displacement), and double replacement (or ionic).

Lab #1-5

Purpose To observe chemical reactions in order to determine their types; to practice writing chemical equations.

Prediction Based on the directions, which reaction do you think will be the most interesting? Why do you think so?

Equipment beaker (600 mL) Bunsen burner forceps small test tubes stirring rod striker

test tube holders tongs wash bottle watch glass well plate

Materials aluminum foil candle pH paper wooden splints calcium [Ca (s)] calcium oxide [CaO (s)] copper (II) carbonate, basic [CuCO3 ? Cu(OH)2 (s)] copper (II) sulfate, pentahydrate [CuSO4 ? 5H2O (s)]

copper (II) sulfate solution [CuSO4 (aq)] lead (II) nitrate solution [Pb(NO3)2 (aq)] magnesium ribbon [Mg (s)] potassium iodide solution [KI (aq)] silver nitrate solution [AgNO3 (aq)] sodium chloride solution [NaCl (aq)] zinc [Zn (s)]

Safety Considerations

? Several of the chemicals in this lab are slightly to moderately toxic. YOU MUST WEAR GOGGLES AT ALL TIMES.

? The silver and lead-based chemicals are toxic; DO NOT POUR THEM DOWN THE SINK. Instead, pour them in the specially marked waste containers.

? DO NOT look directly at the magnesium ribbon while burning. ? When heating test tubes, keep them slightly tilted and pointed away from yourself and other

students; DO NOT LOOK DOWN INTO THE TEST TUBE.

CP Chemistry

Theodore Roosevelt High School

Lab #1-5

Procedure

Part A ? Single Replacement Reactions 1. Obtain a clean well plate.

a. Place a small piece of zinc metal in one well. Record your observations. b. Fill the well about two-thirds full of copper (II) sulfate solution. c. Observe the zinc and solution. Return to this station later to observe any changes and

record your observations. 2. Repeat step 1, but instead use a small piece of calcium and distilled water in another well plate.

Part B ? Combination Reactions 1. Obtain a small piece of magnesium ribbon. Record your observations of the metal.

a. Light and adjust the Bunsen burner to a hot blue flame. b. Using tongs, hold one end of the magnesium in the hot outer cone of the flame. Once the

magnesium ribbon has ignited, hold it over your lab station. CAUTION: DO NOT LOOK DIRECTLY AT THE BURNING MAGNESIUM. c. Observe the properties of the product. Record your observations. 2. Place a tiny lump of calcium oxide (about the size of a match head) in a clean well of the well plate. Observe and record your observations. a. Fill the well about two-thirds full with distilled water. b. Use the stirring rod to mix the calcium oxide and water. Record your observations. c. Place ? strip of red and ? strip of blue litmus paper on your lab station. d. Using the stirring rod, place a drop of the solution from the well on each litmus strip. Record your observations.

Part C ? Decomposition Reactions 1. Place a small crystal of copper (II) sulfate, pentahydrate in a small, dry test tube. Record your

observations. a. Hold the test tube over the lab station with the mouth of the test tube tilted slightly downwards. Evenly heat the bottom portion of the test tube with a hot flame. Record your observations of the materials being given off from the test tube. b. Allow the test tube to cool in a rack. You may want to complete other stations and then return later. c. After the test tube has cooled completely, add a few drops of water to the contents of the test tube. Note the temperature of the bottom of the test tube. Record your observations.

2. Place a small amount of copper (II) carbonate, basic (about the size of a small pea) in a dry test tube. Record your observations. a. Using a test tube holder, evenly heat the test tube with a hot flame, making observations throughout the procedure. b. When the reaction is complete, allow the material to cool. Record your observations.

Part D ? Double Replacement Reactions 1. Place a few drops of potassium iodide solution in a clean well. Record your observations.

a. Add a few drops of lead (II) nitrate. Record your observations. 2. Repeat step 1, but instead use silver nitrate solution and sodium chloride. CAUTION: silver nitrate

solution can stain skin and clothing.

Part E ? Combustion 1. Place a candle upright on the center of a foil-covered watch glass.

a. Carefully lower a beaker over the lighted candle. b. Observe and record until no more changes are evident. c. Light a splint, carefully lift one edge of the beaker and insert the lighted end into the beaker

next to the candle. Record your observations.

CP Chemistry

Theodore Roosevelt High School

Lab #1-5

Data ? you should create a data table in your lab write-up that looks something like this:

Experiment

A1

single replacement

Reactants (before)

Reaction (during)

Products (after)

A2

single replacement

B1

combination

...etc. for all experiments.

Questions 1. What evidence do you have that the color of copper (II) sulfate pentahydrate is related to the

presence of water in the crystal? 2. Would you predict that the "ash" formed when magnesium burned would have a greater or lesser

mass than the original piece of magnesium metal? Why? 3. What evidence do you have that the product of calcium oxide and water is basic rather than

neutral or acidic?

Errors Describe two possible errors you may have committed in this lab that may have somehow affected your results. Explain the specific steps you will take to avoid each of these errors in the future.

Conclusion Write two or more paragraphs summarizing your results, examining the validity of your prediction, and identifying the unknown metal ions.

CP Chemistry

Theodore Roosevelt High School

Types of Chemical Reactions Lab workspace:

Lab #1-5

 ................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download