BELL WORK: WELCOME BACK1. Choose a new seat next to someone new in a new

part of the room.2. What was the best part of your break that included

an ionic compound? (name the compound too)3. What was the best part of your break that included

a covalent compound? (name the compound too)4. Name a chemical change that you observed over

the break.5. Which type of reaction was your break most like?

(synthesis, decomposition, single or double?) Why?

WELCOME BACK TO CHEMISTRY!We are going to review how to write formulas and balance equations . . .

WE WILL STEP BY STEP, TRANSLATE A SENTENCE INTO A BALANCED CHEMICAL REACTION.

1. Copper (II) chloride reacts with aluminum foil to form aluminum chloride and solid copper metal.

FIRST WE NEED FORMULAS. . . .

Copper (II) chloride

Step 1: Is the compound ionic or covalent?

Ionic

Step 2: What are the oxidation numbers?

Cu+2 and Cl-1

Step 3: Cross the charges to create a compound with a zero net charge.

CuCl2

Copper (II) chloride reacts with aluminum foil to form aluminum chloride and solid copper metal.

WHAT’S THE FORMULA FOR ALUMINUM?Al

What’s the formula for Aluminum Chloride?

Step 1: Is the compound ionic or covalent?

Ionic

Step 2: What are the oxidation numbers?

Al+3 and Cl-1

Step 3: Cross the charges to create a compound with a zero net charge.

AlCl3

Copper (II) chloride reacts with aluminum foil to form aluminum chloride and solid copper metal.

WHAT’S THE FORMULA FOR COPPER?Cu

Now we can write the equation:

CuCl2 + Al –> AlCl3 + Cu

What type of reaction is this?

There’s one more step . . . . . .

Copper (II) chloride reacts with aluminum foil to form aluminum chloride and solid copper metal.

WE MUST HAVE A BALANCED EQUATION!

____ CuCl2+ ____ Al –> ____ AlCl3 + ____ Cu

Step 1: List elements or polyatomic ions under both sides.Cu CuCl ClAl Al

WE MUST HAVE A BALANCED EQUATION!

____ CuCl2+ ____ Al –> ____ AlCl3 + ____ Cu

Step 2: List how many of each are present in the reaction.Cu 1 Cu 1Cl 2 Cl 3Al 1 Al 1

WE MUST HAVE A BALANCED EQUATION!____ CuCl2+ ____ Al –> ____ AlCl3 + ____ Cu

Step 3: Add numbers in front of compound as needed to make the reactants equal the products.Cu 1 Cu 1Cl 2 Cl 3Al 1 Al 1

What law does this step follow?

WE WILL STEP BY STEP, TRANSLATE A SENTENCE INTO A BALANCED CHEMICAL REACTION.

2. Lead Nitrate reacts with potassium iodide to form potassium nitrate and a lead iodide precipitate.

FIRST WE NEED FORMULAS. . . .

Step 1: Is the compound ionic or covalent?

Step 2: What are the oxidation numbers?

Step 3: Cross the charges to create a compound with a zero net charge.

One point for each correct formula written in 4 minutes.

Lead Nitrate reacts with potassium iodide to form potassium nitrate and a lead iodide precipitate.

WHAT TYPE OF REACTION IS THIS?There’s one more step . . . . . .

Write out the unbalanced equation.

One point for type of reaction, one point for correct unbalanced equation in 2 minutes.

WE MUST HAVE A BALANCED EQUATION!

_____Pb(NO3)2 +_____KI _____KNO3 + _____ PbI2

Step 1: List elements or polyatomic ions under both sides.

Step 2: List how many of each are present in the reaction.

Step 3: Add numbers in front of compound as needed to make the reactants equal the products.

4 points for a correctly balanced equation in 4 minutes.

WE WILL STEP BY STEP, TRANSLATE A SENTENCE INTO A BALANCED CHEMICAL REACTION.

3. Hydrogen Peroxide (dihydrogen dioxide) breaks down into oxygen gas and water.

FIRST WE NEED FORMULAS. . . .THEN AN EQUATION.

Hydrogen Peroxide (dihydrogen dioxide) breaks down into oxygen gas and water.

4 minutes:One point for each correct formula written in an unbalanced equation in.One point for the type of reaction.

WE MUST HAVE A BALANCED EQUATION!

____ H2O2 → ____ H2O + ____ O2

4 points for a correctly balanced equation in 4 minutes.

CAN YOU DO IT ALL TOGETHER?

Calcium carbonate breaks down into calcium oxide and carbon dioxide.

CAN YOU DO IT ALL?

Calcium carbonate breaks down into calcium oxide and carbon dioxide.

8 minutes:Correctly balanced equation ( 5 points)Type of equation ( 2 points)Which compound is covalent? ( 1 point)

A LITTLE DIFFERENT DIRECTION:

Solid calcium combines with oxygen gas in a synthesis reaction.

5 minutes:2 points for the correct product(s)5 points for the correctly balanced equation

Hydrochloric acid reacts with sodium hydroxide to form sodium chloride and water.

8 minutes:5 points for correctly balanced equation.2 points for correct reaction type.1 point for identifying the law that the reaction follows.

LAST ONE. . . .