Chemical reactants are substances that undergo a chemical reaction to form new substances. There are several types of chemical reactants based on their roles and participation in reactions. Here are some common types of chemical reactants: Reactants These are the primary substances that undergo a chemical change during a reaction. Reactants are consumed during the reaction and are transformed into products. Example: In the combustion of methane ( � � 4 CH 4 ​ + � 2 O 2 ​ → � � 2 CO 2 ​ + � 2 � H 2 ​ O), methane ( � � 4 CH 4 ​ ) and oxygen ( � 2 O 2 ​ ) are the reactants. Precipitates Precipitates are solid substances that form during a chemical reaction in a solution. They are often formed when two aqueous solutions react and a solid product (precipitate) is insoluble and separates from the solution. Example: Mixing solutions of silver nitrate ( � � � � 3 AgNO 3 ​ ) and sodium chloride ( � � � � NaCl) results in the formation of a white precipitate of silver chloride ( � � � � AgCl). Acids and Bases Acids and bases are types of reactants that participate in acid-base reactions. Acids donate protons ( � + H + ) while bases accept protons. Example: In the reaction between hydrochloric acid ( � � � HCl) and sodium hydroxide ( � � � � NaOH), � � � HCl (acid) reacts with � � � � NaOH (base) to produce water ( � 2 � H 2 ​ O) and sodium chloride ( � � � � NaCl). Oxidizing and Reducing Agents Oxidizing agents gain electrons and are reduced during a reaction. Reducing agents lose electrons and are oxidized during a reaction. Example: In the reaction of iron ( � � Fe) with oxygen ( � 2 O 2 ​ ), oxygen acts as the oxidizing agent, while iron acts as the reducing agent to form iron oxide ( � � 2 � 3 Fe 2 ​ O 3 ​ ). Catalysts Catalysts are substances that speed up chemical reactions by lowering the activation energy, but they themselves are not consumed or permanently changed. They provide an alternative pathway for the reaction to occur more rapidly. Example: Enzymes in biological systems act as catalysts for various metabolic reactions. Solvents Solvents are substances in which reactions take place or in which reactants are dissolved. They do not undergo a chemical change themselves during the reaction. Example: Water ( � 2 � H 2 ​ O) is a common solvent used in many chemical reactions, particularly in aqueous solutions. These are some fundamental types of chemical reactants based on their roles and behaviors in chemical reactions. Depending on the nature of the reaction and the substances involved, various combinations of these reactant types can participate to produce new products.

1. Focus Activity: What is the
conservation of matter? What
does it show you?
Homework: Read and Answer 6.2
questions 1, 2, 3 and Section 6.3 all
questions due Wed

2. • Place your model on the appropriate table
around the room.
• Make sure your name is on it.
• Put your name(s) on your rubric and put the
rubric on TOP of your model.
• There will be a sign up sheet coming around-
fill in who you handed your project into and if
it was an email attachment/poster/shared on
google docs.

3. Types of Chemical Reactions
*Synthesis – The get together
*Decomposition- The break up
*Single Replacement- The Cheater
*Double Replacement- The Swap
*Combustion
**The Red names are “helpful hints”

6. Reactants – beginning substance Products- Ending Substance

7. Coefficient- number placed in front of a chemical formula in an equation.

21. This compound must be a hydrocarbon- made of Hydrogen and
Carbon.

22. H20 and CO2 will always be a product

23. CH4 + 2 O2 → CO2 + 2 H2O
***All Combustion must have a
hydrocarbon and 02 as
reactants

24. Some fun with Chemical Reactions!!
http://www.youtube.com/watch?v=dxlWtsFinTM

25. Let’s React!
• Synthesis- what will be on the produce side?
• 2Na + Cl2 → 2 NaCl (formation of table salt)
• Decomposition- what 2 elements/compounds
are products?
• 2 H2O2 → 2 H2O + O2

26. • Single Replacement/displacement
• Zn + 2 HCl → ZnCl2 + H2
• Double Replacement/Displacement
• HCl + NaOH → NaCl + H2O

27. • Combustion
• 2 CH2 + O2 → 2 C02 2H2O

28. Focus Activity: Describe in your own words
why you think the different types of
chemical reactions could be called “The
Get Together”, “The Break Up”, “The
Cheater”, and “The Swap”.
• Study for your quiz on Thursday- Information
from Friday, Monday, Tuesday, and
Wednesday’s notes will be on the quiz.

29. How to make a reaction occur…
•Activation Energy: minimum amount of energy needed to start a chemical reaction
Rates of Chemical Reactions
•Surface Area – The more surface area that is exposed, the faster the reaction will
occur- Example- chewing your food breaks it into smaller pieces with more surface
area. It takes less time to digest your food.
•Temperature- The higher the temperature
the faster the particles move. This means
they interact more often and have more
Energy. Example: Storing Milk in the fridge slows down reactions to stay fresher
longer.

30. More ways to control a reaction
• Concentration- the amount of substance in a given volume.
Increasing the concentration allows for more particles to
react.
• Catalyst- material that increases the rate of
reaction by lowering the activation energy
• Enzymes- Cells in your body that acts as catalysts.
• Inhibitor- material used to decrease the rate of a reaction

31. Every Chemical Reaction
displays a change in Energy!!!!!
http://www.youtube.com/watch?v=tE4668aarck

32. Time for Practice Worksheets!!

33. Answers to 6.1
• 1A. Physical Properties can be observed without changing the substance into
another. Chemical Property: Characteristic of a substance that describes its ability
to change into another substance.
• B. You could ask whether the black crust formed from silver and water? If it is,
then the silver underwent a chemical change, because a new substance was
formed.
• C. Chemical Bonds form between atoms that share, gain, or lose electrons, or
bonds break and new bonds form.
• 2A. Change in color, precipitate forms, gas bubbles, change in texture, change in
energy.
• B. Cooked eggs are solid, raw are liquid. Color changes.
• C. Both types of reactions show a change in energy. Endothermic absorbs energy,
exothermic releases energy.

34. Answers to 6.2
• 1A. Formulas tell you the elements and compounds involved
in the reaction, arrow means “Yields” and points to the
products. + indications 2 or more reactants or products.
• B. Both reactants and products are written as formulas.
Reactants are placed to the left of the arrow and products are
on the right.
2A Conservation of Mass means no matter is created or
destroyed during a chemical reaction.
B 250g
3A. Synthesis, decomposition, and replacement
B 2
C Synthesis

35. Answers to 6.3
• 1A Minimum amount of energy needed to start a chemical reaction.
• B All chemical reactions need a certain amount of activation energy
to get started.
• C Students might say that both endothermic and exothermic
reactions need a similar level of activation energy in order to begin.
• 2A Chemists can control the rates of chemical reactions by changing
factors such as surface area, temperature, and concentration, and
by using substances called catalysts and inhibitors.
• B Sugar crystals, because more particles of sugar are exposed than
in a sugar cube.