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
Dec 24, 2015
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 around- fill 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.
H20 and CO2 will always be a product
CH4 + 2 O2 → CO2 + 2 H2O
***All Combustion must have a hydrocarbon and 02 as reactants
Some fun with Chemical Reactions!!
http://www.youtube.com/watch?v=dxlWtsFinTM
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
• Single Replacement/displacement
• Zn + 2 HCl → ZnCl2 + H2
• Double Replacement/Displacement
• HCl + NaOH → NaCl + H2O
• Combustion
• 2 CH2 + O2 → 2 C02 2H2O
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 meansthey 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=tE4668aarck
Time for Practice Worksheets!!
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.
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 250g3A. Synthesis, decomposition, and replacementB 2C Synthesis
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.