Ch4 Lec 7

Welcome to your first online lecture. Get your notepad out and write on top...Chapter 4, Lecture 7 (Review/Copper Cycle Lab/Molarity).

When we started Chapter 4: Reactions in Aqueous Solutions on 2/24/20, we discussed that there were 3 types of reactions that we were going to cover:

- Section 4.2: Precipitation Reactions, including ionic equations, and net ionic equations,

- Section 4.3 Acid-Base Reactions including neutralization rxn and gas forming reactions, and

- Section 4.4: Oxidation Reduction Reactions including 1/2 rxns, assigning oxidation numbers, LEO-GER...and more!

Review

- Let's review...please write the term in your notes and then a short definition for the following:

1) Solute

2) Solvent

3) Solution

4) Electrolyte

5) Non-electrolyte

6) Strong electrolyte

7) Weak electrolyte

Precipitation Reactions

- Write a short definition of what a precipitation reaction is...

- I did a demonstration in class were i reacted lead nitrate with potassium iodide. I technically started with solids of each of these reactants, but "pushed" them into the large drop of water turning them into aqueous solutions...pls write out this chemical reaction in your notes...(remember a ppt rxn generates a solid/insoluble product - this is when we use our solubility table)

- Write out the ionic equation for the demonstration rxn...

- Wite out the net ionic equation for the demonstration rxn..

- If you did your homework (assigned in class, not WA) from before, then you will have a sheet with 5 precipitation reactions. Please include this sheet in your online notes or if you never did it, here is the worksheet to complete.

Acid-Base Reactions

- Write in your notes the chemical formulas for the following acids:

• Hydrochloric acid -->
• Nitric Acid -->
• Sulfuric Acid -->
• Phosphoric Acid -->

- What make the above chemicals acids?

- Write in your notes the chemical formula or the following bases:

• Sodium hydroxide
• Magnesium hydroxide
• Potassium hydroxide
• Ammonia

- What makes these chemicals bases?

- What is the chemical formula for the hydronium ion and write out a reaction showing this as a product...

- There are two types of acid-base reactions we discussed in class:

1) Neutralization Rxn, and

2) Gas forming Rxn.

Neutralization Rxn

- Write in your notes an example of a neutralization rxn...balance and include physical states.

- Now write out the ionic equation for this neutralization rxn...

- Now write out the net ionic equation for this neutralization rxn...

NOTE: all acid-base neutralization rxns have the same net ionic eq.

Gas Forming Rxn

- if a acid-base reaction involves the following ions, then it produces the stated gas:

• HCO₃^- (aq) --> CO₂ (g)
• CO₃^2- --> CO₂ (g)
• SO₃^2- (sulfite) --> SO₂ (g)
• S^2- (sulfide)--> H₂S (g) (rotten eggs)

Oxidation-Reduction Reactions

Crash Course Video