Ecology Unit Outline

Team Members______Block_____ Dates______

Group I Reactions

A. Write and balance the chemical equation for each of the following reactions. Use phase designations ((s), (l), (g) where indicated. Write each final and correct balanced chemical equation on the top half of an index card.

1) Red phosphorus is dropped into a test tube filled with chlorine gas. (Birds chirping in the background are not necessary.)

http://www.youtube.com/watch?v=UHxXmHg2_yk

2) Aluminum is heated then added to bromine.

http://www.youtube.com/watch?v=2vPe2ML9Jao

3) Iron is mixed with sulfur. Then a hot stirring rod is placed in the mixture.

http://www.youtube.com/watch?v=A5H6DVe5FAI

4) Hot aluminum is put into a flask filled with chlorine.

http://www.youtube.com/watch?v=vrBPCUeqnfM

5) Yellow sulfur is heated and put into an oxygen-filled flask.

http://www.youtube.com/watch?v=V1sQO91UvFI

6) A flask is filled with chlorine. A small amount of sodium metal is placed in the flask. A drop of water is placed on the sodium to initiate the reaction. Note: the water is not involved in the reaction we’re interested in.

http://www.youtube.com/watch?v=Mx5JJWI2aaw

7) Powdered aluminum and powdered iodine are mixed in a crucible.

http://www.youtube.com/watch?v=N5h5ohd8298

8) Zinc and sulfur are mixed then ignited.

http://www.youtube.com/watch?v=7XDF_qw4ohI

9) Red phosphorus is mixed with bromine.

http://www.youtube.com/watch?v=IVZjNeqerdk

B. On the bottom half of the index card answer each of the following three questions in order.

a) How many reactants are present in the reaction?

b) How many products are created in the reaction?

c) What kinds of reactants are used in these reactions? i.e. are they metals, nonmetals, ionic compounds, molecular compounds?

d) What kinds of reactants are used in these reactions? i.e. are they metals, nonmetals, ionic compounds, molecular compounds?

e) What kinds of products are produced in these reactions? i.e. are they metals, nonmetals, ionic compounds, molecular compounds?

C. Organize your collection of cards to identify the general pattern this reaction type follows and then fill out the attached form.

Group II Reactions

1) When an electric current is passed through water, two gases are formed. One of the gases will cause a glowing splint to reignite. The other gas will cause a small explosion with a burning splint.

2) When ammonium dichromate is ignited, it decomposes rapidly, making a “volcano.” The solid green product is chromium (III) oxide. The other two products are nitrogen gas and water vapor.

3) When exposed to light or heat, hydrogen peroxide will decompose, giving off a gas and leaving a clear liquid behind. (This is why hydrogen peroxide is sold in brown bottles, not clear bottles. In a clear bottle it would decompose before you even bought it!) If collected, the gas given off will reignite a glowing splint. Another way to speed up this decomposition is to add a catalyst. The catalyst, in this case manganese (IV) oxide, makes the reaction occur faster but does not actually get changed in the reaction. Therefore, it does not go on the reactant side or the product side. We write it over the arrow instead.

4) When zinc (II) carbonate is heated, it breaks down into carbon dioxide and zinc oxide. http://www.youtube.com/watch?v=9BOBJ_fpLDw

5) One way to produce oxygen gas is to heat potassium chlorate. The byproduct of this process is potassium chloride.

6) When a carbohydrate like sugar is heated, it begins to caramelize and turn brown. This can taste really good. However, if you keep heating, all that will be left behind is a chunk of black solid. That solid is pure carbon. Based on the name “carbohydrate,” can you figure out what the other decomposition product is?

7) Octanitrocubane has the chemical formula C8N8O16 and the structure shown below.

This structure is highly strained, and octanitrocubane decomposes spontaneously and rapidly, making it a very powerful explosive (so powerful, in fact, that it is nearly impossible to isolate and store. It was first synthesized in 1999, but has not been produced on a wide scale to date). The decomposition products are nitrogen and carbon dioxide.

8) TNT, trinitrotoluene, is a commonly used explosive. Its structure is shown below.

When ignited in an enclosed space, it decomposes into carbon monoxide, carbon, nitrogen, and water. The structure of TNT is shown to the left. (Note: This equation may be tough to balance).

B. On the bottom half of the index card answer each of the following three questions in order.

a. How many reactants are present in the reaction?

b. How many products are created in the reaction?

c. What kinds of reactants are used in these reactions? i.e. are they metals, nonmetals, ionic compounds, molecular compounds?

d. What kinds of products are produced in these reactions? i.e. are they metals, nonmetals, ionic compounds, molecular compounds?

C. Organize your collection of cards to identify the general pattern this reaction type follows and then fill out the attached form.

Group III Reactions

1. Here are two reactions . First potassium chromate reacts with silver nitrate. Second potassium iodide reacts with lead (II) nitrate. http://www.youtube.com/watch?v=opY3FLrPTa4

2. Magnesium chloride and sodium sulfate do not react.

3. Copper (II) hydroxide precipitates out of solution when copper nitrate is mixed with sodium hydroxide. http://www.youtube.com/watch?v=_5MRdFJX7Ts

4. A reaction occurs when sodium hydrogen carbonate solution reacts with potassium dichromate. http://www.youtube.com/watch?v=Pk1P_2a5-Wo

5. This video shows 5 different reactions, all of the same type. Write and balance each equation. http://www.youtube.com/watch?v=xqVCP0A9hDY&feature=related

6. Sodium carbonate and potassium fluoride do not react when mixed.

B. On the bottom half of the index card answer each of the following three questions in order.

a) How many reactants are present in the reaction?

b) How many products are created in the reaction?

c) What kinds of reactants are used in these reactions? i.e. are they metals, nonmetals, ionic compounds, molecular compounds?

d) What kinds of products are produced in these reactions? i.e. are they metals, nonmetals, ionic compounds, molecular compounds?

e) Which reactions didn’t happen?

f) What is the pattern that predicts which reactions happen and which don’t happen?

C. Organize your collection of cards to identify the general pattern this reaction type follows and then fill out the attached form.

Group IV Reactions

1. Copper chloride reacts with aluminum foil in one reaction and reacts with magnesium in a second reaction. http://www.youtube.com/watch?v=hKtynbVtMKc

2. Hydrochloric acid removes zinc from copper pennies

http://www.youtube.com/watch?v=QQ0eLyBzKYs

3. Another money changing move. Write the single replacement reaction for the first part of this demonstration. http://www.youtube.com/watch?v=iPhtMDCgSc0

4. Iron does not react with magnesium sulfate

5. Getting silver out of solution. http://www.youtube.com/watch?v=LpgOqiU8dws&feature=related

6. When silver is mixed with potassium nitrate, no chemical reaction occurs

7. Harvesting platinum from scrap: http://www.youtube.com/watch?v=cT7IMbDYkc8&feature=related

8. Calcium reacts with water: http://www.youtube.com/watch?v=AvjC7TAm21E

9. Aluminum reacts with copper (II) sulfate: http://www.youtube.com/watch?v=S5fUAzTqg68

10. Aluminum does not react with sodium sulfate.

2) On the bottom half of the index card answer each of the following three questions in order.

a) How many reactants are present in the reaction?

b) How many products are created in the reaction?

c) What kinds of reactants are used in these reactions? i.e. are they metals, nonmetals, ionic compounds, molecular compounds?

d) What kinds of products are produced in these reactions? i.e. are they metals, nonmetals, ionic compounds, molecular compounds?

3) Organize your collection of cards to identify the general pattern this reaction type follows and then fill out the attached form.

Group V Reactions

Write and balance the chemical equation for each of the following reactions. Use phase designations ((s), (l), (g) where indicated. Write each final and correct balanced chemical equation on the top half of an index card.

1) Hydrogen gas burns explosively when ignited in the presence of oxygen. This reaction is responsible for the destruction of the Hindenburg. http://www.youtube.com/watch?v=lFptgQ8GA_U&feature=related

2) Natural gas consists mostly of methane, CH4. Many homes and businesses burn natural gas furnaces for heat.

3) Acetylene is a gas that is used to power welder’s torches. If a large amount of acetylene is burned at once, an explosion can occur. The chemical formula for acetylene is C2H2. http://www.youtube.com/watch?v=X1LwYJ8pDhc

http://www.youtube.com/watch?v=RoatgaQrK28&feature=related

4) Octane (C8H18) is one component of gasoline. You may have heard of the “octane rating” of gasoline. This rating does not indicate the percentage of octane in the gas. Rather, it compares the way the gas burns in an engine to the way a mixture of octane and heptanes (another compound) would burn under the same conditions.

5) Ethanol can be found in products ranging from alcoholic beverages to mouthwash to gasoline. There has been significant debate over whether using ethanol to supplement and replace gasoline is cost effective and environmentally sound. Ethanol has the formula C2H6O and burns readily in oxygen.

http://www.youtube.com/watch?v=hT0v0Z7qabw and http://www.youtube.com/watch?v=2BUFwnyVnIg

6) Iron rusts (turns into iron (III) oxide) when exposed to air for a period of time. We would not usually classify this as combustion. However, if iron is exposed to an environment of 100% oxygen (as opposed to the 20% in air), it reacts much more violently. This reaction might be called combustion. http://www.youtube.com/watch?v=XhhJZ55JPxo

7) Propane (C3H8) is used to heat homes, run generators, and most importantly operate grills that cook delicious food.

8) Sugar is essentially burned slowly by the body, reacting with oxygen in our cells. The energy from this reaction is harnessed for us to live. Table sugar (sucrose) has the chemical formula C12H22O11.

9) Magnesium burns very brightly when ignited. The flame is so intense that you are advised not to look directly at it. http://www.youtube.com/watch?v=RaIZ__BhC6M

10) Methanol (CH3OH) is found in many brands of windshield washer fluid. It is a toxic chemical that causes blindness in small amounts. It burns in oxygen with a virtually colorless flame.

11) Butane (C4H10) is commonly used as the fuel for lighters.

2) On the bottom half of the index card, answer each of the following questions in order.

a) How many reactants are present in the reaction?

b) How many products are created in the reaction?

c) Which of the above did not react?

d) What kinds of reactants are used in these reactions? i.e. are they metals, nonmetals, ionic compounds, molecular compounds?

e) What kinds of products are produced in these reactions? i.e. are they metals, nonmetals, ionic compounds, molecular compounds?

f) What is the pattern that permits you to know who reacts and who doesn’t react?

3) Organize your collection of cards to identify the general pattern this reaction type follows and then fill out the attached form.

Reaction Group Members ______

Write a general equation that shows how the reactants are altered to become products: e.g. AB + C à A + BC

Describe the types of reactants involved in this reaction type:

Describe the type of products produced in this reaction type:

Select the best three representative examples of balanced chemical equations for this type of reaction and write them below

Additional Comments: Is there additional information that is needed to determine whether the reaction will happen. Include the information here.