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Chemical Equations
Prentice Hall Chapter 3 Chemical Equations
18
Science
8th Grade
03/08/2015

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Term
Starts the Reaction
Definition
The activation energy of a chemical reaction: is supplied by a catalyst, is released at the end, starts the reaction, or changes with time.
Term
Combustion Reaction
Definition
A chemical reaction in which a fuel combines rapidly with oxygen is an: inhibited reaction, combustion reaction, enzyme reaction, endothermic reaction?
Term
Synthesis Reaction
Definition
A chemical reaction in which 2 elements combine to form a compound.
Term
Exothermic
Definition
A chemical that gives off heat
Term
Firefighters open doors very slowly why?
Definition
Opening the door suddenly lets oxygen into the room. The added oxygen allows the fire to flare up.
Term
How are inhibitors useful in controlling chemical reactions?
Definition
the work by preventing reactants from coming together or combining.
Term
How do enzymes in your body make chemical reactions occur at safe temperatures?
Definition
they bring the reactant molecules closer together so it lowers the activation energy needed
Term
How does the energy of the product compare with the energy of the reactants?
Definition
The energy of the products is greater than the energy of the reactants.
Term
Some statues are made with materials that can react to acid rain and begin to dissolve. Very smooth statues dissolve slower than statues with intricate carvings
Definition
Detailed carvings provide more surface area for the acid rain to attach to and react with.
Term
Steel that is exposed to water and salt rusts quickly. If you were a shipbuilder, how would you protect your ship?
Definition
Paint the steel or cover it with a different kind of protectant
Term
Tell wether the diagram is Exo or Endo Thermic?
Definition
The reaction is endo thermic? How in the heck do you know that Nix?! :-)
Term
What are two kinds of changes that occur in matter? Describe how you can tell one from the other.
Definition
2 kinds are Chemical and Physical changes. A physical change does not change a substance into another substance. A chemical change DOES change a substance into another substance
Term
What change in condition might account for the lower HUMP in the second graph?
Definition
The use of a catalyst might account for the lower "HUMP" in the second graph. This is because a catalyst is a material that lowers the activation energy.
Term
Why can't you balance a chemical equation by changing the subscripts of the reactants or the products?
Definition
Changing subscripts changes the chemical formula all together! DUH!
Term
Why does spraying water on a fire help extinguish it?
Definition
Because it removes part of the fire triangle. Oxygen. Right Nix?
Term
Which of the following is not a physical property? Flexibility, ability to catch fire, melting point, ability to conduct electricity.
Definition
Ability to catch fire dude
Term
You can balance a chemical equation by changing the : subscripts, coefficients, reactants, or products? Well? Which one?
Definition
Coefficients (What else?)
Term
You find a mass of a piece of iron metal, let it rust, and measure the mass again. The mass has increased. Does this violate the principal of conservation of MASS?
Definition
No because a chemical change occurred where a new substance was created, which actually added more MASS.
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