Quizlet 10.2

What is a decomposition reaction?

A chemical reaction in which a single compound is broken down to produce two or more smaller compounds is called a decomposition reaction.

What do (s), (l), (g), and (aq) stand for?

(s)- solid (l)- liquid (g)- gas (aq)- aqueous substance is dissolved in solution

What is a precipitate and what does it form in the solution?

A precipitate is a solid product that comes out of solution in a chemical reaction (insoluble) and precipitates usually form many small particles which cause a cloudy appearance in a solution

How can a reaction start by itself?

A reaction starts by itself when thermal energy is greater than the activation energy.

What is activation energy? Give me an example

Activation energy is the energy needed to start a reaction and break chemical bonds in the reactants. That is why gasoline does not burn without a spark or flame. The spark supplies the activation energy to start the reaction

Compare nuclear and chemical reactions.

Chemical involve the outer electrons, Nuclear involves the nucleas, Chemical rearrange atoms into new molecules but the atoms stay the same, nuclear atoms may change into atoms of a different element. Chemical uses small amount of energy, nuclear uses a huge amount of energy.

What two ways are energy involved in chemical reactions?

Energy is involved in chemical reactions in two ways. (1) At the start of a chemical reaction, some (or all) bonds between atoms in the reactants must be broken so that the atoms are available to form new bonds. (2) Energy is released when new bonds form as the atoms recombine into the new compounds of the products.

What is an endothermic reaction, and what does it do?

If forming new bonds in the products releases less energy than it took to break the original bonds in the reactants, the reaction is endothermic. Endothermic reactions absorb energy.

What is an exothermic reaction?

If forming new bonds releases more energy than it takes to break the old bonds, the reaction is exothermic.

What is an addition reaction?

In an addition reaction, two or more substances combine to form a new compound.

What are single-displacement reactions?

In single-displacement reactions, one element replaces a similar element in a compound.

How are mass and energy conserved in nuclear reactions?

Mass and energy are conserved together but not separately in nuclear reactions.

What reaction involves more energy: chemical or nuclear? Why?

Nuclear reactions involve much more energy than chemical reactions. The energy in a nuclear reaction is much greater because nuclear reactions involve the strong nuclear force, the strongest force in the universe

What is petroleum, and what is refining?

Petroleum is not a single substance but a complex mixture of many substances created over millions of years by the decay of plants and animals. The refining process separates petroleum into molecules with different numbers of carbon atoms (combustion reactions)

What is polymerization? What are polymers?

Polymerization is a series of addition reactions that join small molecules into very long chain molecules. Polymers are large molecules made up of repeating segments.