# C2 P2: Reaction equations lecture 2.

C2 lecture 2: Reaction equations
Learning objectives:
1. You can use the phase symbols for substances.
2.  You can use a description of a chemical reaction to work out the reaction equation.
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Slide 1: Tekstslide
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In deze les zitten 10 slides, met tekstslides.

Lesduur is: 45 min

## Onderdelen in deze les

C2 lecture 2: Reaction equations
Learning objectives:
1. You can use the phase symbols for substances.
2.  You can use a description of a chemical reaction to work out the reaction equation.

#### Slide 1 -Tekstslide

Reaction equation
What do you remember of the last lecture?
what are the 5 steps to balance a reaction equation ?

#### Slide 2 -Tekstslide

From reaction to equation

#### Slide 3 -Tekstslide

From reaction to equation

Step-by-step plan to a correct reaction equation.

Step 1. Write down the word equation.

Step 2. Replace the names of the substances by their formulas

Step 3. Balance the reaction equation.
Check which type of atoms appear at 2 places. Choose one of them and put coefficients in front of those two formulas to have the same amount of the chosen type of atom on both sides.
- Choose the lowest numbers possible. What always works (but is not always the lowest): 3 x 2 = 2 x 3
Continue with the next type of atom. Choose one of which you are only missing 1 coefficient.
When u have a fraction instead of  a whole number, multiply all coefficients until you do by the denominator (number below)

#### Slide 4 -Tekstslide

From reaction to equation
Step-by-step plan to a correct reaction equation.

Step 4. Check if you can simplify the reaction equation. If possible, you must do so.

Step 5. Double check if every molecular formula has a coefficient. Remove all coefficients that are equal to 1. When a molecule appears only once, the coefficients is not written down in your final answer.

Example

Step 1.

Step 2.

Step 3a.

Step 3b.

Step 4.

Step 5.

#### Slide 6 -Tekstslide

Lets work!
Do you have questions about the home work ?
Make: Exercises 1 through 6.

#### Slide 7 -Tekstslide

Homework HT3a
Read: Chapter 2 paragraph 2. Reaction equations
Make: All the exercises.

#### Slide 8 -Tekstslide

Lets work!
Do you have questions about the home work ?
Make: Exercise 3.

#### Slide 9 -Tekstslide

Homework HT3b
Read: Chapter 2 paragraph 2. Reaction equations
Make: Exercises 1 through 3.