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