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WorksheetsChemical Bonding and Reactions
Total questions: 40
Worksheet time: 3hrs 16mins
A change in matter that produces new substances is call a
chemical reaction
mixture
physical change
solution
What is one observable characteristic of a chemical reaction?
Change in hardness.
Change in shape.
Bubbles forming.
Change in mass.
A shorter, easier way to show a chemical reaction, using symbols instead of words.
Chemical formula
Chemical reaction
Chemical symbol
Chemical equation
Substances you wind up with after a chemical reaction has occurred.
reactants
products
catalyst
inhibitor
This type of reaction needs energy to get started but then keeps going on its own.
fusion reaction
fission reaction
endothermic reaction
exothermic reaction
Materials that increase the rate of a reaction.
catalyst
inhibitor
lowering the temperature
decreasing the concentration of reactants
If you wanted to decrease the rate of reaction, what action would you need to take?
decrease the temperature
insert a catalyst
increase the surface area
double the reactants
Mg +CuCl2 = MgCl2 + Cu
Which type of reaction is shown above?
synthesis
decomposition
replacement
combustion
A chemical change is different than a physical change because in a chemical change
Chemicals are used
Molecules do not physically touch
A new substance is formed and in a physical change no new substance is formed
The change can be seen but in a physical change it cannot
In a chemical reaction
The atoms of the reactants always stay together to form the products
The atoms of the reactants unbond, rearrange, and then rebond to form the products
New atoms are formed which combine to make the products
Some atoms disappear while others multiply to form the products
In a chemical reaction, mass is conserved. This means that
The mass of the reactants stays the same during a chemical reaction
The mass of the products stays the same during a chemical reaction
The type and number of atoms in the reactants equals the type and number of atoms in the products
The mass of the products is always twice the mass of the reactants.
If more reactants are used in a chemical reaction, more products will be produced. This is because
More reactants cause the reaction to heat up
More reactants take up the same volume
More reactants have more atoms to react to form more products
Too many products can slow down the reaction
One clue of a chemical change is the formation of a precipitate. A precipitate is formed when
Two liquids react and a gas is produced
A solid dissolves in a liquid
One liquid dissolves in another
Two liquids react and a solid is formed
In a chemical reaction, if the reactants are heated, the reaction usually happens
Faster
Slower
At the same rate
In a smaller volume
Some chemical reactions require a substance called a catalyst. The main purpose of a catalyst is
To warm up the reaction
To speed up the reaction
To create more reactants
To stop the reaction
If two substances react and the temperature of the mixture increases, the reaction is
Endothermic
Not one that produces anything new
One that needs a catalyst
Exothermic
If two substances react and the temperature of the mixture decreases, the reaction is
Endothermic
Never going to happen unless it is heated
Exothermic
one that causes atoms to be destroyed
A substance that enters into a chemical reaction is called a
coefficient
product
subscript
reactant
In a reaction in which hydrogen reacts with oxygen to produce water, which substances are the reactants?
hydrogen only
oxygen only
both hydrogen and oxygen
water
Which of the following is NOT an example of a chemical change?
rusting iron
an apple ripening
cutting paper
a piece of wood burning
In a chemical equation, the symbol that takes the place of the words reacts with is a(n)
equal sign
coefficient
plus sign
arrow
In a chemical equation, the number of molecules of a given substance is indicated by a
subscript.
coefficient
superscript
reaction number
In balancing a chemical equation, which of the following are you allowed to do?
change subscripts
write coefficients
change superscripts
add new substances
According to the law of conservation of mass, the total mass of the reacting substances is
always more than the total mass of the products
always less than the total mass of the products.
sometimes more and sometimes less than the total mass of the products
always equal to the total mass of the products
Chemical reactions ____.
occur only in living organisms
create and destroy atoms
only occur outside living organisms
produce new substances
In a combustion reaction, one of the reactants is ____.
hydrogen
nitrogen
oxygen
a metal
What is the Law of Conservation of Mass?
It states that matter can be created or destroyed.
It states no energy can be created or destroyed.
It states that no sound can be created or destroyed.
It states that no mass can be created or destroyed in a chemical reaction.
A + B → AB : is the general form for which reaction type?
Synthesis reaction
Decomposition reaction
Replacement reaction
Combustion reaction
Identify the type of reaction: Ca + O --> CaO
Synthesis reaction
Decomposition reaction
Replacement reaction
Combustion reaction
Which reaction type is the following:
2Na + CaF2 --> Ca + 2NaF
Snythesis reaction
Decomposition reaction
Replacement reaction
Combustion reaction
What is a coefficient?
The small number on the right of the chemical symbol.
The large number to the left of a formula.
What coefficient should be used to make the following equation balanced?
N2+O2--> _____NO
1
2
3
4
Fill in the missing coefficient to balance the equation: Mg + ___ HCl → MgCl2 + H2
1
2
3
4
What happens to some of the mass when bubbles are formed during a chemical reaction?
stays the same
escapes as a gas
absorbed into each other
nothing
What type of bonds are present in a strip of magnesium ribbon?
Metallic bonding
Ionic bonding
Covalent bonding
Which particles may be gained, lost, or shared by an atom when it forms a chemical bond?
neutrons
protons
electrons
Which type of bond is formed by the transfer of electrons from one atom to another?
ionic
covalent
metallic
Generally, how many valence electrons are needed for atoms to be most stable?
8
6
32
18
What type of bond forms when atoms share electrons?
ionic
metallic
covalent
How many atoms of carbon are used to make a molecule of sugar, C12H22O11?
12
11
22
sugar is not a molecule
