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Chemical reactions tutorial

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Chemical reactions tutorial. Let’s get started!!. Goals. In this tutorial, you will learn… How to recognize 3 of the 5 types of reactions Predict the products of reactions when only given the reactants. What are the 5 types of reactions?. Which 3 will be we learning about??. SYNTHESIS. - PowerPoint PPT Presentation
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CHEMICAL REACTIONS TUTORIAL Let’s get started!!
Transcript
Page 1: Chemical reactions tutorial

CHEMICAL REACTIONS TUTORIAL

Let’s get started!!

Page 2: Chemical reactions tutorial

Goals

In this tutorial, you will learn…

How to recognize 3 of the 5 types of reactions

Predict the products of reactions when only given the reactants

Page 3: Chemical reactions tutorial

What are the 5 types of reactions?

Synthesis

Decomposition

CombustionSingle replacement

Double replacement

Page 4: Chemical reactions tutorial

Which 3 will be we learning about??

Synthesis

Decomposition

Combustion

Page 5: Chemical reactions tutorial

SYNTHESIS

Page 6: Chemical reactions tutorial

Synthesis

Two or more reactants combine to form… ONE

PRODUCT!!

A + B

AB

Page 7: Chemical reactions tutorial

Synthesis Continued

Mg + O2 MgOTwo reactants form one product

BUT WAIT!!Don’t forget about everything you have already

learned! Is your equation balanced??

2 2

Page 8: Chemical reactions tutorial

Before we keep going… lets learn a few things about predicting products

Predicting products

Page 9: Chemical reactions tutorial

Predicting products

Here are a few important things to remember when predicting products: The compounds form must be neutral

ionic compounds (which means you’ll be paying attention to their charges)

You do NOT carry subscripts from the reactants to the products.

You always balance your equation LAST

Page 10: Chemical reactions tutorial

Let’s go back to that synthesis example Remember the reaction:

Mg + O2 Helpful hint for later…why is

oxygen O2 and not just O?Click to find

out why

Page 11: Chemical reactions tutorial

Why O2??

What are the other diatomic elements? (hint: remember the heavenly 7!

Oxygen is a diatomic molecule, which means when oxygen is

by itself it must be O2. Remember that this DOES NOT

mean that oxygen is O2 in compounds, only by itself!

Go back

H2 I2

Br2 O

2

N2 Cl

2

F2

Page 12: Chemical reactions tutorial

Now to predict the products…

Remember A + B AB so Mg + O2 will make a compound with magnesium and oxygen. What

does a compound with magnesium and oxygen look

like??

Mg + O2

Page 13: Chemical reactions tutorial

A compound with magnesium and oxygen…

Magnesium is a metal, oxygen is a nonmetal so we must be forming an IONIC compound.What’s the charge of Mg?

Mg 2+

What’s the charge of O?

O 2-

Page 14: Chemical reactions tutorial

So what’s the compound?

Mg2+

O2-Pick…

MgO2

Mg2O2

MgO

Page 15: Chemical reactions tutorial

Nope!

+2 + 2(-2)

DOES NOT EQUAL ZERO

MgO2

Try again!

Page 16: Chemical reactions tutorial

Nope!

2(+2) + 2(-2) = 0

But remember ionic compounds need to be in the simplest form

Mg2O2

Try again!

Page 17: Chemical reactions tutorial

Yes! Very good!

MgO is a neutral, correct ionic compound so our formula is

Mg + O2 MgOFinally, balance the equation to satisfy the law of conservation of mass…

2Mg + O2 2MgO

Page 18: Chemical reactions tutorial

So remember…

When predicting products: Make correct ionic compounds THEN balance

Let’s move on to the rest of the reaction types…

Page 19: Chemical reactions tutorial

Decomposition

Page 20: Chemical reactions tutorial

Decomposition

forms two or more productsONE

REACTANT…

A + BAB

Page 21: Chemical reactions tutorial

Decomposition Continued

The electrolysis of water is when water decomposes into hydrogen and oxygen gas as shown below:

2H2O 2H2 + O2

Page 22: Chemical reactions tutorial

Predicting products and decomposition Lets use that same reaction. What if

we were not already given the products, how would we predict them?H2O ??

Water is made of hydrogen and oxygen,

so will my products just be H and O?

Page 23: Chemical reactions tutorial

No!

Remember, H and O are both diatomic elements.

H2O H2 + O2But

wait….something is still missing….

Page 24: Chemical reactions tutorial

Balance!

Don’t forget to balance your equation after you make your products! Your final answer should look like this:

2H2O 2H2 + O2

Page 25: Chemical reactions tutorial

You try one…

What is the correct reaction for the decomposition of sodium chloride, NaCl?

NaCl Na + Cl

2NaCl 2Na + Cl2

2NaCl Na2 + Cl2

Page 26: Chemical reactions tutorial

Nope!

Don’t forget that chlorine is a diatomic element, so it must be Cl2

NaCl Na + Cl

Try again!

Page 27: Chemical reactions tutorial

Nope!

Although this reaction is correctly balanced, sodium is NOT a diatomic element

2NaCl Na2 + Cl2

Try again!

Page 28: Chemical reactions tutorial

Yes! Very good!

This is a correct reaction for the decomposition of sodium chloride.

2NaCl 2Na + Cl2

Ready for the last type of reaction?

Page 29: Chemical reactions tutorial

Combustion

Page 30: Chemical reactions tutorial

Combustion Combustion is the burning of

hydrocarbons. Hydrocarbon?? What’s that?? Click to find out!

When a hydrocarbon reacts with oxygen (O2), the products are ALWAYS…..

Yes, ALWAYS…Carbon dioxide and water CO2 + H2O

Page 31: Chemical reactions tutorial

Hydrocarbons

A hydrocarbon is an organic molecule made up of hydrogen and carbon. Remember when we learned about these when we talked about organic chemistry??

CH4

C6H10

C20H4

2

Page 32: Chemical reactions tutorial

Combustion Cont…

Since the products of a combustion reaction are always CO2 and H2O, the hardest part about combustion reactions is balancing them

CH4 + O2 CO2 + H2O

Balance this equation…

Page 33: Chemical reactions tutorial

Combustion Cont.

Be aware… this reaction was pretty easy to balance, some of the combustion reactions get pretty complicated! Like this one…

CH4 + O2 CO2 + 2H2O

4C3H9 + 21O2 12CO2 + 18H2O

Page 34: Chemical reactions tutorial

Ready for your quiz??

Yes!

Not quite, review the types of reactions

with me…

Page 35: Chemical reactions tutorial

Review Synthesis reactions: two or more

reactants combine to form ONE product

A + B AB Decomposition reactions: ONE reactant breaks down into two or more products

AB A + B Combustion reactions: a hydrocarbon

reacts with oxygen to produce carbon dioxide and water.

Hydrocarbon + O2 CO2 + H2O

Ok, now I’m ready for the quiz!

Page 36: Chemical reactions tutorial

Quiz Question 1/5

Which of the following is a decomposition reaction?

2Fe + O2 2FeO

Na + AgCl Ag + NaCl

Na2S 2Na + S

Page 37: Chemical reactions tutorial

Nope!

This is two reactants forming ONE product which is an example of a synthesis reaction

2Fe + O2 2FeO

Try again!

Page 38: Chemical reactions tutorial

Nope!

This reaction does not just form one product. This reaction is an example of a single replacement reaction which we will learn about later.

Na + AgCl Ag + NaCl

Try again!

Page 39: Chemical reactions tutorial

Yes! Very good!

This reaction is ONE reactant breaking down into two or more products, which is an example of a decomposition reaction.

Na2S 2Na + S

Next question

!

Back to the

question!

Page 40: Chemical reactions tutorial

Quiz Question 2/5

How can you recognize a combustion reaction?

A combustion reaction is the only reaction always has at

least two reactants and two products. One of the reactants is always oxygen

gas.

A combustion reaction always

has a hydrocarbon reacting with

oxygen to produce carbon dioxide

and water.

A combustion reaction always

has a hydrocarbon reacting with

nitrogen, which is a very explosive

reaction.

Page 41: Chemical reactions tutorial

Nope!

We will learn about other reactions that can have more than one product and more than one reactant. This is NOT the way to identify a combustion reaction.

Try again!

A combustion reaction is the only reaction always has at

least two reactants and two products. One of the reactants is always oxygen

gas.

Page 42: Chemical reactions tutorial

Nope!

Although combustion reactions are typically explosive, it is not because they react with nitrogen.

Try again!

A combustion reaction always

has a hydrocarbon reacting with

nitrogen, which is a very explosive

reaction.

Page 43: Chemical reactions tutorial

Yes! Very good!

This is how we identify a combustion reaction

Next question

!

A combustion reaction always

has a hydrocarbon reacting with

oxygen to produce carbon dioxide

and water.

Back to the

question!

Page 44: Chemical reactions tutorial

Quiz Question 3/5

Pick correct bubble that finishes the reaction below.

K + Cl2 ??2K + Cl2

2KCl

K + Cl2 KCl2

K + Cl2 KCl

Page 45: Chemical reactions tutorial

Nope!

Remember to not carry subscripts over to your products. K has a +1 charge and Cl has a -1 charge so the product of KCl2 is not neutral and cannot be correct. Try

again!

K + Cl2 KCl2

Page 46: Chemical reactions tutorial

Almost! But not quite…

Although this product is correct, the equation is not balanced!

Try again

!

K + Cl2 KCl

Page 47: Chemical reactions tutorial

Yes! Very good!

The products are correct and the reaction is balanced! Great job!

Next questio

n!

2K + Cl2 2KCl

Back to the

question!

Page 48: Chemical reactions tutorial

Quiz Question 4/5

Pick correct rectangle that finishes the reaction below.

C2H8 + O2 ??C2H8 + O2 CO2 +

H2O

C2H8 + O2 C2H8O2

C2H8 + 4O2 2CO2 + 4H2O

Page 49: Chemical reactions tutorial

Almost, but not quite…

Great job predicting the products, but…. don’t forget to balance!!

Try again!

C2H8 + O2 CO2 + H2O

Page 50: Chemical reactions tutorial

Nope!

Remember that combustion reactions always have carbon dioxide and water as products

Try again!

C2H8 + O2 C2H8O2

Page 51: Chemical reactions tutorial

Yes! Very good!

Products are correct and the equation is correctly balanced. Great job!

Back to the

question!Next

question!

C2H8 + 4O2 2CO2 + 4H2O

Page 52: Chemical reactions tutorial

Quiz Question 5/5

Pick correct rectangle that finishes the reaction below.

Al + N2 ??Al + N2 AlN2

3Al + N2 Al3N2

2Al + N2 2AlN

Page 53: Chemical reactions tutorial

Nope!

Remember we do not carry over subscripts. Aluminum has a +3 charge and nitrogen has a -3 charge so a formula of AlN2 is not a neutral compound

Try again!

Al + N2 AlN2

Page 54: Chemical reactions tutorial

Nope!

Although this equation is balanced, since aluminum has a +3 charge and nitrogen has a -3 charge, this is not a neutral compound

Try again!

3Al + N2 Al3N2

Page 55: Chemical reactions tutorial

Yes! Very good!

A correct neutral compound for the product and a balanced equation. Great!

Finish!

Back to the question!

2Al + N2 2AlN

Page 56: Chemical reactions tutorial

You have finished the chemical reactions tutorial

Congratulations!

Go back to the start


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