Which of the following changes is chemical rather than physical? a. Water is boiled c.

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Transcript Which of the following changes is chemical rather than physical? a. Water is boiled c.

Slide 1

Which of the following changes is
chemical rather than physical?
a. Water is boiled

c. Glass is shattered

b. Aluminum foil is crumpled

d. Wood is burned


Slide 2

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

c. Precipitate

b. Product

d. Catalyst


Slide 3

When the following chemical
reaction is balanced, what number is
placed before NH3?

N2 + 3H2

__ NH3

a.

1

c.

3

b.

2

d.

4


Slide 4

A substance that speeds up
chemical reactions without
changing itself is a(n)
a. Inhibitor

c. Enzyme

b. Catalyst

d. Prohibitor


Slide 5

What type of reaction is
FeS + 2HCl
FeCl2 + H2S?
a. A Synthesis Reaction
b. A Decomposition Reaction
c. A Single-Replacement Reaction
d. A Double-Replacement Reaction


Slide 6

A chemical equation that shows the
same number and kind of atom on
both sides of the equation is said to
be
a. Balanced
b. Unbalanced
c. An incomplete reaction
d. A replacement reaction


Slide 7

Anything that has mass and takes
up space is considered
a. Matter

c. Chemistry

b. Energy

d. Endothermic


Slide 8

What happens when chemical
bonds break and new bonds form?
a. A physical change
b. A chemical reaction
c. Matter is destroyed
d. Surface area increases


Slide 9

CaCO3 represents a chemical
a. Symbol

c. Equation

b. Formula

d. Reaction


Slide 10

A shorter, easier way to show
chemical reactions, using symbols
instead of words, is called a
a. Chemical Equation

c.

Symbol

b. Chemical Formula

d.

Subscript


Slide 11

The substances listed on the left
side of a chemical equation are the
a. Products

c. Precipitates

b. Coefficients

d. Reactants


Slide 12

Which of the following is a
balanced chemical equation?
a. H2O2

H2 O + O 2

b. 2 Fe2O3 + 3C
c. SO2 + O2 + 2H2O
d. 2Mg + HCl

4Fe + 3CO2
4H2SO4
MgCl2 + H2


Slide 13

A chemical reaction that absorbs
energy in the form of heat is
described as
a. Endothermic

c. Combustion

b. Exothermic

d. Unbalanced


Slide 14

The minimum amount of energy
that has to be added to start a
reaction is the
a. Exothermic Reaction

c.

b. Endothermic Reaction

d. Chemical Energy

Activation Energy


Slide 15

A material used to decrease the
rate of a chemical reaction is a(n)
a. Inhibitor

c. Enzyme

b. Catalyst

d. Fuel


Slide 16

In a chemical equation, numbers
often appear in front of a chemical
formula. These numbers tell you the
a. Number of atoms in each molecule in the reaction
b. Number of elements in the reaction
c. Number of molecules or atoms of each substance in the reaction
d. Number of molecules in each atom in the reaction


Slide 17

Chemicals that act as biological
catalysts by speeding up reactions
in living things are
a. Inhibitors

c. Fuels

b. Enzymes

d. Reactants


Slide 18

The number placed below an
element’s symbol
a. Subscript

c. Reactant

b. Coefficient

d. Product


Slide 19

Which of the following chemical
equations is balanced?
a. 3Ca + O2
b. 3Ca + 2O2
c. Ca + 2O2
d. Ca + O2

3CaO2
5CaO2
2CaO2
CaO2


Slide 20

Which of the following is an
example of a chemical reaction?
a. Ice melting in a glass of water
b. Paper turning soft when wet
c. Salt crystals forming as sea water evaporates
d. Leaves changing colors in the fall


Slide 21

How many Carbon atoms are in
this glucose molecule?
C6H12O6
a.

3

c.

12

b.

6

d.

24


Slide 22

How many sodium (Na) ions are
in this molecule?
7Na3PO4
a.

3

c.

21

b.

7

d.

28


Slide 23

What occurs when water freezes?
a. A physical change
b. A chemical reaction
c. A chemical bond
d. A diatomic molecule


Slide 24

What is the force that holds atoms
together called?
a. A chemical solution
b. A chemical mixture
c. A chemical reaction
d. A chemical bond


Slide 25

Which is the product in this
chemical formula?

N + O2

NO2

a. N

c.

O2

b.

d.

NO2

O


Slide 26

Which of these uses coefficients
correctly to balance this equation?
N2 + H2
a. N2 + 3H2
b. 2N2 + 2H2
c. N2 + H2
d. 3N2 + 4H2

NH3
2NH3
4NH3
NH3
6NH3


Slide 27

Which of the following states the
law of conservation of mass?
a. Atoms are rearranged in a chemical reaction, and some join new molecules
b. Two compounds combine to form a new compound with different properties
c. Mass cannot be created nor destroyed in a chemical reaction
d. Energy is neither created nor destroyed in a chemical reaction


Slide 28

How many oxygen atoms are
present in the reactant in this
chemical equation?
4Fe + 3O2

2Fe2O3

a.

2

c.

4

b.

3

d.

6


Slide 29

Which of the following is an
example of a diatomic molecule
a. NaCl

c.

Mg

b. O2

d.

CaCl2


Slide 30

How many atoms are present in
the formula CaCO3?
a.

Three

c.

Five

b.

Four

d.

Six


Slide 31

If a chemical symbol in a chemical
formula has no subscript, it means
a.

The chemical symbol is written without any numbers

b.

The element has no charge

c.
d.

The chemical is listed last in the formula
Only one atom of the element is in the molecule


Slide 32

Which phrase describes what
happens to atoms in a chemical
reaction?
a. Sometimes lost, never rearranged
b. Sometimes lost, gained, or rearranged
c. Never lost or gained, just rearranged
d. Lost or gained, never rearranged


Slide 33

What must be done for a chemical
equation to be balanced?
a. All molecules must be counted
b. All chemicals must be equal
c. All atoms must be counted
d. All atoms must be discounted


Slide 34

Which of the following shows an
exothermic reaction?
a. 2Na + Cl2

2NaCl + energy

b. 2H2 + O2

2H2O

c. 2H2O + energy
d.

6CO2 + 6H2O + energy

2H2 + O2
C6H12O6 + 6O2


Slide 35

What happens in an endothermic
reaction?
a. Energy is destroyed
b. Energy is released
c. Energy is created
d. Energy is taken in


Slide 36

Which of the following chemical
reactions illustrates a
decomposition reaction?
a. 2H2O
b. 4H2 + O2

2H2 + O2
2H2O

c. 6CO2 + 6H2O + energy
d. 4KI + 2Cl

C6H12O6 + 6O2

4KCl + 2I2


Slide 37

Which of the following chemical
reactions illustrates a Synthesis
reaction?
a. 2H2O
b. 4H2 + O2

2H2 + O2
2H2O

c. 6CO2 + 6H2O + energy
d. 4KI + 2Cl

C6H12O6 + 6O2

4KCl + 2I2


Slide 38

Which of the following chemical
reactions illustrates a SingleReplacement reaction?
a. 2H2O
b. 4H2 + O2

2H2 + O2
2H2O

c. 6CO2 + 6H2O + energy
d. 4KI + 2Cl

C6H12O6 + 6O2

4KCl + 2I2


Slide 39

Which of the following chemical
reactions illustrates a Endothermic
reaction?
a. 2H2O
b. 4H2 + O2

2H2 + O2
2H2O

c. 6CO2 + 6H2O + energy
d. 4KI + 2Cl

C6H12O6 + 6O2

4KCl + 2I2