HONORS REDOX: PART 1

In our Chemical Reaction Lab, we added COPPER METAL TO SILVER NITRATE SOLUTION - What happened?

The equation for this reaction is: Cu(s) + 2AgNO 3 (aq) → 2Ag(aq) + Cu(NO 3 ) 2 (aq) What type of reaction is this?

Write the complete ionic equation for this reaction.

Write the net ionic equation

You can separate this complete reaction into 2 half-reactions.

The number of electrons lost and gained in a reaction must be equal. What Law demands this? You can use this fact to help balance difficult equations.

For example: the space shuttle is lifted off the earth by this tough redox reaction: NH 4 ClO 4 + Al → Al 2 O 3 + HCl + N 2 + H 2 O

Label each of the substances

The copper atoms lost electrons; i.e., they were The silver atoms gained electrons; i.e., they were

Oxidation is the process in which a substance ____________electrons. Reduction is the process in which a substances_____________electrons. If you have one of these processes, you ___________________ the other.

An oxidation-reduction reaction (redox for short) is:

How will you remember which is oxidation and which is reduction?

An oxidizing agent is A reducing agent is

In our copper and silver reaction, A) What is the oxidizing agent? B) What is the reducing agent?

Some “real-life” examples of redox reactions…

Another example of a redox reaction…combustion!

This is a redox process by which your body stores energy. You will talk about this in biology next year.

These types of reactions are _________________redox reactions. Single replacement Combustion Combination Decomposition Double replacement

We will be doing a demonstration that includes redox reactions. The demo is called the “Hindenburg.” What do you know about the Hindenburg?

In the early 1930’s, passenger air travel was through dirigibles (giant blimps). They were filled with hydrogen gas, because it is lighter than air. The Hindenburg (1936) was the “pride” of Nazi Germany – and capable of crossing the Atlantic Ocean.

What happened to the Hindenburg? There exists actual historic video footage of what happened to the Hindenburg – which we’ll see now!

In our demonstration, we will create a model of the Hindenburg. First, we will do a redox reaction to generate hydrogen gas by adding aluminum foil to hydrochloric acid. We will use the hydrogen gas to fill a balloon, thus creating our own little “airship,” circa 1936.

What is the balanced equation for aluminum + hydrochloric acid?

Write the complete ionic equation

Write the net ionic equation

a) What is being oxidized? b) What is being reduced? c) What is the oxidizing agent? d) What is the reducing agent?

Write and balance the half reactions

For each of the following reactions, A) Write the net ionic equations. B) Write the half-reactions and balance C) Write which element has been oxidized, and which has been reduced. D) Write which element has been the oxidizing agent, and which the reducing agent 1) 3Mg + 2Al(NO 3 ) 3 → 3Mg(NO 3 ) 2 + 2Al 2) 2Li + CaCl 2 → 2LiCl + Ca 3) 6K + 2H 3 PO 4 → 2K 3 PO 4 + 3H 2

1)3Mg + 2Al(NO 3 ) 3 → 3Mg(NO 3 ) 2 + 2Al

2)2Li + CaCl 2 → 2LiCl + Ca

3. 6K + 2H 3 PO 4 → 2K 3 PO 4 + 3H 2

Final note: the reaction which destroyed the Hindenburg was also a redox reaction! 2H 2 + O 2 → 2H 2 O These are molecules, not ionic compounds. How can they have oxidation #’s if they don’t have ions? Stay tuned!