ttuisd 8B Lesson 5/ chemical reactions
The only balanced equation shown below is:
A. CaCl2 → 2Ca + Cl2 B. Ag + H2S → Ag2S + H2 C. Zn + Ag2S → ZnS + Ag D. 3Fe2O3 + CO → 2Fe3O4 + CO2 Correct
Which of the following is an example of an exothermic reaction?
a charcoal fire to cook
Minimum amount of energy needed to start a chemical reaction
activation energy
To start a chemical reaction a minimal amount of energy is needed. This energy is called
activation energy.
Is the following equation balanced or unbalanced? 2Al + 3I2 → 2AlI3
balanced
Is the following equation balanced or unbalanced? CH4 + 2O2 → CO2 + 2H2O
balanced
s the following equation balanced or unbalanced? 3Fe2O3 + CO → 2Fe3O4 + CO2
balanced
There is evidence that a chemical change has occurred when
carbon dioxide gas is produced.
Substance that speeds up a chemical reaction but is not used up itself or permanently changed
catalyst
Process that produces a chemical change, resulting in new substances that have properties different from those of the original substances
chemical reaction
Chemical reaction in which heat energy is absorbed
endothermic
Chemical reaction in which heat energy is released
exothermic
Heat is released in a/an __________ reaction.
exothermic
You can speed up the rate of a reaction by
increasing temperature.
BHT is a/an __________ that is found in many cereals and cereal boxes
inhibitor
Substance that slows down a chemical reaction, making the formation of a certain amount of product take longer
inhibitor
You can slow the ripening of fruits by putting them in the refrigerator because the refrigerator
lowers the reaction rate.
Substance that forms as a result of a chemical reaction
product
Measurement of how fast a reaction occurs
rate of reaction
Substance that exists before a chemical reaction begins
reactant
In an exothermic reaction, the word energy is often written with the products to tell you that energy is
released
Many catalysts __________ reaction rates by providing a surface for the reaction to take place.
speed up
Is the following equation balanced or unbalanced? Ag + H2S → Ag2S + H2
unbalanced Correct