Focus Activity What is the conservation of matter

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

• 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 aroundfill in who you handed your project into and if it was an email attachment/poster/shared on google docs.

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”

Reactants – beginning substance Products- Ending Substance

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

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

H 20 and CO 2 will always be a product

***All Combustion must have a hydrocarbon and 02 as reactants CH 4 + 2 O 2 → CO 2 + 2 H 2 O

Some fun with Chemical Reactions!! http: //www. youtube. com/watch? v=dxl. Wts. Fin. TM

Let’s React! • Synthesis- what will be on the produce side? • 2 Na + Cl 2 → 2 Na. Cl (formation of table salt) • Decomposition- what 2 elements/compounds are products? • 2 H 2 O 2 → 2 H 2 O + O 2

• Single Replacement/displacement • Zn + 2 HCl → Zn. Cl 2 + H 2 • Double Replacement/Displacement • HCl + Na. OH → Na. Cl + H 2 O

• Combustion • 2 CH 2 + O 2 → 2 C 02 2 H 2 O

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.

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.

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

Every Chemical Reaction displays a change in Energy!!!!! http: //www. youtube. com/watch? v=t. E 4668 aarck

Time for Practice Worksheets!!

Answers to 6. 1 • • • 1 A. 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. 2 A. 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.

Answers to 6. 2 • 1 A. 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. 2 A Conservation of Mass means no matter is created or destroyed during a chemical reaction. B 250 g 3 A. Synthesis, decomposition, and replacement B 2 C Synthesis

Answers to 6. 3 • 1 A 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. • 2 A 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.