Chapter 19 Science Test

Front 1

Each substance written to the right of the arrow in a chemical equation is a _____.

Back 1

Product

Front 2

Name a chemical change.

Back 2

Wood burning

Front 3

How does the mass of the products in a chemical reaction compare to the mass of the reactants?

Back 3

The masses are always equal

Front 4

Name a change that gives NO evidence that a chemical reaction has taken place.

Back 4

A cube of solid forms a puddle of liquid

Front 5

A factor that would not speed up a chemical reaction.

Back 5

Increasing the concentration of a reactant

Front 6

Materials that will burn the fastest in open air.

Back 6

A pile of small splinters made from a two foot diameter log

Front 7

The burning of gasoline in an automobile engine is an example of a(n)_____.

Back 7

Exothermic reaction

Front 8

The most common form of energy encountered in chemical reactions is _____.

Back 8

Heat

Front 9

In a chemical reaction, energy can be _____.

Back 9

Neither created or destroted

Front 10

An example of a process in which entropy decreases is _____.

Back 10

Freezing

Front 11

The main source of energy for living things on Earth is _____.

Back 11

Solar energy

Front 12

The major product formed during the process of photosynthesis is _____.

Back 12

Sugar

Front 13

In a _____ reaction, the products are at a higher energy level than are the reactants.

Back 13

Exothermic

Front 14

Even in an exothermic reaction, _____ is needed to get the reaction started.

Back 14

A catalyst

Front 15

The energy involved in endothermic and exothermic reactions is _____.

Back 15

Heat

Front 16

The energy released in the formation of a compound from its elements is always _____ the energy required to decompose that compound into its elements.

Back 16

Identical to

Front 17

If the heat of reaction is negative, the reaction is _____.

Back 17

Endothermic

Front 18

Spontaneous reactions occur if energy ____ and disorder _____.

Back 18

Decreases, Increases

Front 19

When bowling pins at the end of an alley are hit by a bowling ball, the entropy of the pins _____.

Back 19

Increases

Front 20

In the processes that produce electricity, some of the energy used is wasted as _____ energy.

Back 20

Heat

Front 21

Carbon dioxide + water + sunlight + chlorophyll = sugar and oxygen

Back 21

Photosynthesis

Front 22

What reaction is characterized by a net absorption of energy?

Back 22

Endothermic

Front 23

Why are fossil fuels a rich source of energy?

Back 23

Heat is released when fossil fuels combine with oxygen

Front 24

A _____ chemical equation has the same number of atoms of each element on each side of the equation.

Back 24

balanced

Front 25

Each substance on the left side of the arrow in a chemical reaction is a _____.

Back 25

reactant

Front 26

The energy required to break the original bonds is less than the energy release when new bonds form in a _____.

Back 26

exergonic

Front 27

If heat must be added to a chemical reaction for the reaction to take place, the reaction is _____.

Back 27

Endothermic

Front 28

Type of reaction in which 2 or more reactants combine to form a single product.

Back 28

Synthesis

Front 29

Type of chemical reaction in which a single compound breaks down into two or more elements or new compounds.

Back 29

Decomposition

Front 30

When one element replaces another element in a compound, the reaction is a _____ reaction.

Back 30

single-displacement

Front 31

A substance that speeds up a chemical reaction without being permantly changed itself is a _____.

Back 31

catalyst

Front 32

Substances that prevent, or slow down, chemical reactions is called _____.

Back 32

inhibitor

Front 33

Chemical reaction in which heat energy is released is _____.

Back 33

exothermic

Front 34

#'s that precede symbols and formulas in a chemical equation are _____.

Back 34

coeffiecients

Front 35

Insoluble compound forms during chemical reaction?

Back 35

Precipitate