Quiz about Chemical Reactions

Question 1

According to the Law of Conservation of Mass, 3 atoms of calcium react to produce 6 atoms of calcium.

Accepted Answer

false

Answer

true

Question 2

Energy is needed to break chemical bonds in chemical reactions.

Accepted Answer

true

Answer

false

Question 3

An endothermic reaction is one in which more energy is absorbed than is released.

Accepted Answer

true

Answer

false

Question 4

All chemical reactions occur at the same rate.

Accepted Answer

false

Answer

true

Question 5

Activation energy is the minimum amount of energy needed for a chemical reaction to begin.

Accepted Answer

true

Answer

false

Question 6

When a chemical reaction contains the same number of atoms on both sides, the equation is balanced.

Accepted Answer

true

Answer

false

Question 7

Lowering the temperature slows down most chemical reactions.

Accepted Answer

true

Answer

false

Question 8

The rate of reaction is the speed at which products form or reactants disappear.

Accepted Answer

true

Answer

false

Question 9

Which of the following changes is chemical rather than physical?

Accepted Answer

wood is burned

Answer

water is boiled

Answer

aluminum foil is crumpled

Answer

glass is shattered

Question 10

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

Accepted Answer

product

Answer

reactant

Answer

precipitate

Answer

catalyst

Question 11

According to the Law of Conservation of Mass, the mass of the products in a chemical reaction is ___ the mass of the reactants.

Accepted Answer

equal to

Answer

not related to

Answer

greater than

Answer

less than

Question 12

Which of the following factors does NOT speed up a chemical reaction?

Accepted Answer

making the reactant particles larger

Answer

increasing the concentration of the reactants

Answer

adding a catalyst

Answer

raising the temperature

Question 13

Substances formed during chemical reactions are ___.

Accepted Answer

products

Answer

catalysts

Answer

oxides

Answer

reactants

Question 14

The presence of a(n)___ speeds up a reaction.

Accepted Answer

catalyst

Answer

reactant

Answer

product

Answer

inhibitor

Question 15

For a chemical reaction to begin, ___ is needed.

Accepted Answer

activation energy

Answer

combustion

Answer

a catalyst

Answer

a spark

Question 16

To check that an equation is balanced, count the number of ___ on each side of the equation.

Accepted Answer

atoms of each type

Answer

ions

Answer

molecules

Answer

types of elements

Question 17

The molecule H₂C₂H₃O₂ has ___ atoms.

Accepted Answer

9

Answer

4

Answer

11

Answer

6

Question 18

In an endothermic reaction, ___ is absorbed.

Accepted Answer

energy

Answer

inhibitor

Answer

catalyst

Answer

atoms

Question 19

The ___ is a measure of how fast a reaction occurs.

Accepted Answer

rate of reaction

Answer

catalyst effect

Answer

activation energy

Answer

concentration

Question 20

The presence of a ___ speeds up a reaction.

Accepted Answer

catalyst

Answer

reactant

Answer

product

Answer

inhibitor

Question 21

Adding an inhibitor tends to ___ a reaction.

Accepted Answer

slow down

Answer

have no effect on

Answer

speed up

Answer

reverse

Question 22

Heat is released during ___ reactions.

Accepted Answer

exothermic

Answer

activation

Answer

endothermic

Answer

enzyme

Question 23

The melting of ice is an example of a(n) ___ .

Accepted Answer

physical change

Answer

endothermic reaction

Answer

exothermic reaction

Answer

chemical change

Question 24

The burning of paper is an example of a(n) ___.

Accepted Answer

chemical change

Answer

endothermic reaction

Answer

exothermic reaction

Answer

physical change

Question 25

The size of the reactant particles can effect the ___ of a reaction.

Accepted Answer

rate

Answer

temperature

Answer

product

Answer

concentration

Question 26

The rate of reaction in a chemical change can be measured by how fast a(n) ___ appears.

Accepted Answer

product

Answer

reactant

Answer

exotherm

Answer

activator

Question 27

A ___ is a process in which new substances are formed.

Accepted Answer

chemical reaction

Answer

catalyst

Answer

reactant

Answer

subscript

Question 28

Catalysts ___ the activation energy needed to start a chemical reaction.

Accepted Answer

reduce

Answer

inhibit

Answer

increase

Answer

balance

Question 29

Reactants have their highest concentrations ___ a chemical change takes place.

Accepted Answer

before

Answer

never

Answer

after

Answer

during

Question 30

Chemical reactions usually speed up at ___ temperatures.

Accepted Answer

higher

Answer

constant

Answer

stable

Answer

lower

Question 31

A higher concentration of reactant will speed up a chemical reaction because there will be more ___ between the reactant particles.

Accepted Answer

collisions

Answer

space

Answer

combustion

Answer

bonds

Question 32

A substance that speeds up a chemical reaction in the human body is a(n) ___.

Accepted Answer

enzyme

Answer

inhibitor

Answer

prohibitor

Answer

polar

Question 33

Chemical symbols and numbers used to show the types of atoms and how many of each atom are in a compound are called ___

Accepted Answer

chemical formulas

Answer

chemical reactions

Answer

products

Answer

reactants

Question 34

A chemical ___ is a shorthand method of writing what happens in a chemical reaction.

Accepted Answer

equation

Answer

formula

Answer

catalyst

Answer

inhibitor

Question 35

Which of the following is an example of a physical change?

Accepted Answer

shredding paper

Answer

burning a candle wick

Answer

baking a cake

Answer

frying eggs

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