Unit 6: Chemical Reactions - Mrs. Slovacek's...
Transcript of Unit 6: Chemical Reactions - Mrs. Slovacek's...
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Unit 6: Chemical Reactions
Key Learnings Chemistry Standard/Outcome
1 Physical and Chemical Changes
2 Chemical Reactions
3 Classifying Chemical Reactions
4 Writing Chemical Reactions from Chemical Statements
5 Predicting Products from Reactants
Physical and Chemical Changes
Contrast physical and chemical properties
Classify examples as physical or chemical changes
Chemical Reactions
Understand what happens during a chemical reaction
Understand basic parts of a chemical reaction o Reactants, products, arrow, symbols
Understand why chemical equations need to be balanced o Coefficients and Subscripts
Understand the Law of Mass Conservation
Classifying Chemical Reactions
Classify Five Types of Reactions o Synthesis/Direct/Combination o Decomposition o Single Displacement/Replacement o Double Displacement/Replacement o Combustion
Writing Chemical Reactions from Chemical Statements
Write chemical reactions from chemical statements
Predict Products from Given Reactants
Predict products from given reactants o Predict Products for Single Displacement Reactions o Predict Products for Double Displacement Reactions
Keywords:
Matter
Pure Substance
Element
Compound
Mixture
Heterogeneous Mixture
Homogeneous Mixture
Solution
Physical Properties
Chemical Properties
Physical Change
Chemical Change
Coefficients
Subscripts
Reactants
Products
Chemical Equation
Chemical Reaction
Precipitate
Synthesis
Decomposition
Single Replacement
Double Replacement
Combustion
Diatomic Atom
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Types of Reactions Unit
Date Topic
1/4 Classification of Matter Notes and Practice
1/5 Physical and Chemical Properties and Changes Notes and Practice
1/6 Balancing Equations Notes and Chembalancer Animation
1/9 Balancing Equations Practice
1/10 Balancing Equations Snowman Race
1/11 Identifying Types of Reactions Notes and Practice
1/12 Identifying Types of Reactions Practice
1/13 Writing Formulas Review
1/16 NO SCHOOL-Martin Luther King Jr. Day
1/17 Predicting the Products for Single Replacement Reaction Notes and Practice
1/18 WebAssign
1/19 Predicting the Products for Double Replacement Reactions Notes and Practice
1/20 Double Replacement Reactions Lab
1/23 Predicting the Products of Reactions Practice
1/24 Word Problem Notes and Practice
1/25 Word Problem Notes and Practice and Unit Review
1/26 Types of Reactions Unit Free Response
1/27 Types of Reactions Unit Test
1/4/16 Objective: Students will be able to classify matter. Warm-Up:
1. What is the best and worst part of your break?
2. What are two things that I expect you to be able to know at the end of this unit?
Classification of Matter
: anything that takes up space and has mass.
Matter can be classified into 2 groups:
Pure Substances
Matter that always has exactly the chemical composition.
o Every sample of a given substance has the same properties because a substance has a
fixed, uniform composition.
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2 Types:
o : when all the atoms in a sample of matter are alike.
Cannot be separated into simpler substances by physical or chemical means.
Example:
These have a composition because they are made up
of only one type of atom.
o : a substance composed of two or more different elements
joined by chemical bonds.
Always contains two or more elements joined in a .
Can only be separated by chemical means, not physically.
Example: water, Sodium Chloride, Carbon Dioxide
Mixtures
A combination of two or more pure substances that are not combined.
Substances are held together by physical forces, not chemical.
Each item retains its in the mixture.
o The properties of a mixture can vary because the composition of the mixture can
change.
They can be separated .
2 Types:
o : the parts of a mixture are noticeable
different from one another.
o : the parts of the mixture are evenly
distributed so you can’t distinguish one from another.
Mixtures get even more complicated! There are different types of heterogeneous and
homogeneous mixtures. The way to tell them apart is by the .
o Heterogeneous Mixtures
: a heterogeneous mixture that separates into
layers over time.
Examples: nail polish, paint, some juices.
How to determine if it’s a suspension:
o Substance will separate into over time.
o You can separate the particles with a filter.
o Particles are large enough to scatter light. This means the
mixture will appear “ .”
: contains particles that are medium to small in
size. A colloid can contain particles of all sizes mixed together.
Examples: chocolate milk, orange juice
How to determine if it’s a colloid:
o Substance does into layers over
time.
o You can’t separate the particles with a filter.
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o Contains many different particle sizes so it will scatter light.
This means the mixture will appear “ ”.
o Homogeneous Mixture
: a liquid that has non-visible particles spread
evenly.
Examples: salt water, windshield wiper fluid.
How to determine if it’s a solution:
o Does not separate into layers over time.
o Cannot separate the parts with a filter.
o Particles are so that they do not
scatter light. This means you can see through them!
1/5/16 Objective: Students will be able to determine if a change is physical or chemical. Warm-Up: Chemistry in a Bag Objective: What observations can be made to indicate that a chemical reaction has occurred? Materials: sealable baggie, plastic spoon, calcium chloride, baking soda, water, paper towels, graduated cylinder, methylene blue. Procedure:
1. Add two spoonful’s of calcium chloride and one spoon full of baking soda to the sealable baggie. 2. Add 50mL of water to a beaker or cup. Add two drops of the methylene blue to the water. 3. Remove as much air as possible from the baggie and partially seal it. Leave a small opening to
use to pour the water into the baggie. 4. Pour the water into the baggie and quickly seal it. Look, listen and feel.
Observations: Question: Did a chemical reaction occur? How do you know?
Physical and Chemical Properties and Changes Physical Properties
properties are those that we can determine changing
the identity of the substance we are studying.
o Examples of physical properties:
Density
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Color
Odor
Texture
Chemical Properties
Describe the way a substance can or react to form other substances.
These properties, then, must be determined using a process that changes the identity of the
substance.
o Examples:
-the ability of a substance to burn or ignite.
-the likelihood that a substance will undergo a chemical
reaction.
Physical Change
Affects one or more physical properties of a substance changing
the identity of the substance.
o Change in or
o Change in
o Dissolving
Chemical Change
One or more substances change into a substance that has different properties.
o The are into something new.
Evidence of a chemical change
o Production of
o Unexpected change in or
o Release of , sound, or
o Formation of a
1/6/16 Objective: Students will be able to apply the Law of Conservation of Mass to balance chemical equations. Warm-Up: Use the following vocabulary words to complete the graphic organizer: matter, pure substance, homogeneous, heterogeneous, compound
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Balancing Equations
: Mass cannot be created or destroyed.
It can only be rearranged.
Nothing gets lost. Nothing is created from thin air. Everything that goes must
also come the other side.
Coefficients and Subscripts
The small numbers after the element symbols are the . They
apply only to the element immediately before it and tell of those
elements there are.
o Example: H2O means there are H’s and O
The large number in front is the . They act as .
You multiply the entire compound that follows by the coefficient.
o Example: 2H2O means there are H’s and O’s
Label the subscripts and coefficients in the following equation:
2H2 + O2 2H2O
Balancing Equations
In a chemical reaction, the substances that undergo change are called .
The reactants are ALWAYS on the side of the equation.
The substances that change are called .
The products are ALWAYS on the side of the equation.
Reactants Products
Label the reactants and products in the following example:
Carbon + Oxygen Carbon Dioxide
A chemical equation represents a chemical reaction in which the reactants and products are expressed
as .
The big idea is that you are trying to get the number of atoms on of
the equation!!!
We can’t just add another atom by changing the subscript. If we did this, it would be a
completely different molecule. Instead, we have to add groups of atoms by changing the
coefficient.
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Rules for balancing equations
1. change the (the little numbers after the element’s
symbols)-this changes the molecule that you are working with,
2. Change the (the big number in front of the atom or molecule)!
3. Watch for (there is a difference between CO and Co)!
4. Always double check your answer!
Steps for Balancing Equations:
1. Make a for reactants and products. List each element/polyatomic ion on each
side of the table. Add the of atoms of each element/polyatomic ion you
are starting with.
2. Start with the element with the number of atoms in a compound. (Balance Na in
Na3PO4 before you balance K in KOH) Save and until you balance the other elements.
3. Leave the element molecules until . (F2 as opposed to H2O)
4. Add a to the beginning of the compound in order to balance out the
atoms.
5. Balance out the remaining atoms in the . Continue until all elements are
balanced.
6. the coefficients when necessary.
Examples:
H2 + O2 H2O
Cu + O2 Cu2O
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1/9/16
Objective: Students will be able to apply the Law of Conservation of Mass to balance chemical equations. Warm-Up: How many atoms do the following compounds contain?
S O Al N H
SO2
A12(SO4)3
2 NH4NO3
1/10/16 Objective: Students will be able to apply the Law of Conservation of Mass to balance chemical equations. Warm-Up: What is wrong with the following chemical equations?
1. 4NH3 + 6I2 2N2I6 + 6H2
2. H2O + 2SO3 H2SO4
1/11/16 Objective: Students will use color coding to help identify the 5 different types of reactions. Warm-Up: Balance the following chemical equations:
1. H2SO4 + Fe Fe2(SO4)3 + H2
2. Mg3N2 + H2O MgO + NH3
Introduction to Types of Chemical Reactions
A is the process by which one or more substances
are changed into one or more different substances.
Indications of a chemical reaction:
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o Production of or
o Production of a
o Formation of a
A precipitate is a that forms when two or more liquids are
combined
o Unexpected Color change
5 Types of chemical reactions:
Type of Reaction Definition Equation
Synthesis
+
Decomposition
+
Single Replacement
+ +
Double Replacement
+ +
Combustion
+ O2 +
Colors: A=Red B=Blue C=Green D=Yellow
Balance each equation. Then, use colored pencils to circle the common atoms or compounds in each
equation to help you determine the type of reaction it illustrates. Use the code below to classify each
reaction.
S=Synthesis D=Decomposition SR=Single Replacement
DR=Double Replacement C=Combustion
1. P + O2 P4O10
2. CuCl2 + H2S CuS + HCl
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3. HgO Hg + O2
4. C3H8 + O2 CO2 + H2O
5. Cl2 + NaBr NaCl + Br2
6. BaCl2 + Na2SO4 NaCl + BaSO4
7. HgO + Cl2 HgCl + O2
8. Mg + O2 MgO
9. Al2O3 Al + O2
10. H2 + N2 NH3
1/12/16 Objective: Students will determine the different types of chemical reactions from a chemical equation. Warm-Up:
1. How can you tell the difference between a synthesis and decomposition reaction?
2. How would you know if a reaction is a single replacement reaction? How do you know it isn’t a synthesis reaction?
1/13/16 Objective: Students will be able to predict the products in a chemical reaction. Warm-Up:
1. Write the ions for the following elements: Cesium, Arsenic, Indium, Magnesium, Iodine, Sulfur
2. What is happening on a subatomic level to create an ion?
Vocabulary Scramble: Use the definition to unscramble the word and write it in the box on the left.
Word Scrambles Word Definition
tarmte
anything that takes up space and has a mass.
pasihcly rrtoppeeis
the properties of matter that can be determined without changing the identity of the substance we are studying.
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efcsoicnieft the number in front of the compound that acts like a multiplier.
ubcissrtps
the small numbers after an element or polyatomic ion that denotes the number of atoms.
hntiseyss
two or more elements or compounds combine to make a more complex substance.
ecioodsmpiotn
compounds break down into simpler substances.
ngsiel eplrenacetm
occurs when one element replaces another one in a compound.
obdeul pelmacrteen
occurs when different atoms in two different compounds trade places.
oocutbmsin when oxygen combines with a hydrocarbon to form water and carbon dioxide.
retcpeitiap a solid that forms when two or more liquids are combined.
Naming and Writing Formulas Review
Type 1:
Naming:
1. The is the name of the element off of the periodic table.
2. The is the root of the element name and the ending – . Polyatomic
endings don’t change.
a. Ex: CaCl2
Writing Formulas:
1. Write the for the elements.
2. Find the of the ions.
3. charges and write the formula.
a. Ex: Aluminum Oxide
Type 2:
Naming:
1. The is the name of the element off the periodic table.
2. Add a for the of the cation.
3. The is the root of the element name and the ending – . Polyatomic
endings don’t change.
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a. Ex: Ag2S3
Writing Formulas:
1. Write the for the elements.
2. Find the of the ions. Remember: the for the cation
is in .
3. Balnce charges and write the formula.
a. Ex: Nickle (II) Bromide
Type 3: Non-Metals and Non-Metals
Naming:
1. The first element is written as its name on the periodic table. The of
atoms is the for that element.
2. The second element is named by: the indicating the number of atoms, the
root of the element’s name and the ending – .
a. Ex: H2O2
Writing Formulas:
1. Write the for the elements off of the periodic table.
2. The tells us how many are present. This is the
element’s .
a. Ex: Dinitrogen Trioxide
1/16/16-NO SCHOOL-Martin Luther King Jr. Day 1/17/16 Objective: Students will be able to predict the products in a chemical reaction. Warm-Up:
1. Write the formula for the following compounds: a. Gold (II) Oxide
b. Aluminum Bromide
2. Write the name of the following formulas (2):
a. NaCl
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b. Fe3P2
Predicting the Products for Single Replacement Reactions Single Replacement Reactions
A element takes the place of a less active element in a compound.
Reactants are composed of a single element and a compound.
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Diatomic Atoms: atoms that are so reactive that they do not exist on their own in nature and
must be written as bonded to themselves.
o H2, N2, F2, O2, I2, Cl2, Br2
To Write the Formula for the Products: 1. Look at the single element. Is it a or a ?
a. Ex: NaBr + Cl2
2. Find the metal/non-metal in the compound. These are the 2
elements that will places.
a. Ex: NaBr + Cl2
3. Write the element with the other element in the compound.
a. The subscripts only transfer IF in a polyatomic!
b. Ex: NaBr + Cl2
4. Write a , followed by the replaced element.
a. If it is a non-metal: it will be a so it needs a 2
subscript.
b. If it is a metal: it is only one atom of that element.
c. Ex: NaBr + Cl2
5. Go back to your compound. Find the of the elements in the
compound.
a. Ex: NaBr + Cl2
6.
a. Ex: NaBr + Cl2
7. the equation.
Examples:
Zn(NO3)2 + Mg
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LiNO3 + Fe3+
1/18/16 Objective: Students will be able to predict the products in a chemical reaction. Warm-Up: Predict the products in the following chemical reactions:
1. Zn2+ + H2SO4
2. Br2 + NaCl
1/19/16 Objective: Students will be able to predict the products in a chemical reaction. Warm-Up: Identify the following as chemical (c) or physical (p) change:
Boiling water
Rust
Cooking a steak
Cutting your hair
Predicting the Products for Double Replacement Reactions
The and of two different compounds switch places.
The reactants are composed of 2 different compounds.
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Steps to Predict the Products: 1. Identify the in the first compound and the in the
second compound.
a. Ex: NaCl + LiBr
2. Write them together on the right side of the equation. Remember: the goes
first!
a. Ex: NaCl + LiBr
3. Find the of the two ions. Balance the charges and write the formula.
a. Ex: NaCl + LiBr
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4. Identify the in the second compound and the in the
first compound.
a. Ex: NaCl + LiBr
5. Write them together on the side of the equation. Remember: the cation
goes first!
a. Ex: NaCl + LiBr
6. Find the charges of the two ions. the and write the
formula.
a. Ex: NaCl + LiBr
7. the equation.
a. Ex: NaCl + LiBr
Examples:
CaCO3 + HCl
BaCl2 + Na2SO4
1/20/16 Objective: Students will be able to predict the products in a chemical reaction. Warm-Up: Identify the type of chemical reaction in the following, and then balance the equation.
1. PbSO4 PbSO3 + O2
2. C2H4 + O2 CO2 + H2O
3. S8 + O2 SO2
1/23/16 Objective: Students will be able to predict the products in a chemical reaction. Warm-Up: Predict the products for the following chemical reactions. (2 equations!)
1. NaBr + H3PO4
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2. Mg + Fe2O3
1/24/16 Objective: Students will be able to predict the products in a chemical reaction. Warm-Up: Write the formula for the following compounds:
1. Magnesium Fluoride
2. Zinc (I) Oxide
3. Aluminum Sulfide
4. Iron (III) Bromide
Writing a Chemical Equation from a Word Equation Steps:
1. Write the for the reactants.
a. are atoms that are never found alone in nature, they
have to be written as 2 atoms together. (A subscript of 2)
2. Find the of your ions and them. Write the
formula. (Remember your Type 1, 2, and 3 review)
3. Add the to your compound.
a. Solid (s)
b. Liquid (l)
c. Gas (g)
d. Solution (aq)
4. Add the math symbols to show what reacts.
a. “And” or “combines” or “poured into” means sign.
b. “Reacts to form” or “to produce” means .
5. Predict the for the reaction.
6. the equation.
Examples
Hydrogen gas and Nitrogen monoxide gas react to form…
A solution of Aluminum Iodide and solid Mercury (II) chloride react to form…
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Describing a Chemical Equation Steps:
1. Name the given . (Remember your Type 1, 2, and 3 review)
2. Describe the .
a. (s) Solid
b. (l) Liquid
c. (g) Gaseous
d. (aq) Solution
3. Consider if the compound is ionically bonded or covalently bonded.
a. : between metals and non-metals
b. : between two non-metals
4. Convert the math symbols to words.
a. = “Add” “Combine” or “Poured into”
b. = “reacts to form” or “to produce”
5. Write the information in format.
Examples:
2ZnS (s) + O2 (g) 2ZnO (s) + 2S (s)
AgNO3 (aq) + NaCl (aq) AgCl (s) + NaNO3 (aq)
1/25/16 Objective: Students will be able to predict the products in a chemical reaction. Warm-Up: Write a chemical equation from the following description:
1. Chlorine gas is added to a solution of Aluminum Bromide to form…
2. What type of chemical reaction is the previous problem? How do you know? 1/26/16 Objective: Students will demonstrate their knowledge of chemical reactions on a review. Warm-Up:
1. How do you know if a given reaction is combustion? What would you look for?
2. What is a diatomic atom? Why are diatomic atoms always written with a subscript 2?
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1/27/16 Objective: Students will demonstrate their knowledge of chemical reactions on a unit exam. Warm-Up: None