WorksheetsChemical Reactions
Total questions: 25
Worksheet time: 25mins
How many atoms of aluminum are on each side of the following equation: 4Al + 3O2 --> 2Al2 O3
2
6
1
4
What does the Law of Conservation of Mass state?
Matter cannot be gained or lost in a chemical reaction.
Matter can only be lost in a chemical reaction.
Matter can only be gained in a chemical reaction.
Matter can be gained and lost in a chemical reaction.
At the end of chemical reactions, what is the total mass of the reactants compared to the total mass of the products?
the product is doubled
the product is half the mass of the reactants
the mass is the same
the mass changes depending on the reaction
a copper penny turning greenish after a few years.
Chemical Change
Physical Change
What is the product of a chemical reaction between an acid and a base?
Salt
Water
Both A and B
Carbon dioxide
Which of the following best describes a chemical reaction?
A process where substances are mixed but not changed
A process where substances are changed into different substances
A process where substances are dissolved in water
A process where substances are separated by physical means
Which type of chemical reaction involves the breaking down of a substance into two or more substances?
Synthesis
Decomposition
Single replacement
Double replacement
What is the result of a chemical reaction?
The starting materials disappear without a trace.
New substances with different properties from the starting materials are formed.
The physical state of the starting materials changes.
The starting materials are recovered unchanged.
What is the result of mixing an acid with a base?
A salt and water
B) A gas and water
C) A salt and a gas
D) A base and a salt
What is the role of chlorophyll in photosynthesis?
It absorbs sunlight.
It produces carbon dioxide.
It converts glucose into energy.
It transports water from the roots to the leaves.
The red numbers in the image below represent ________
subscripts
coefficients
I don't know, and don't want to try
None of the answers are correct
In an exothermic reaction, heat is ...
taken in or absorbed
given out or released
In an endothermic reaction, heat is ...
taken in or absorbed
given out or released
What is the left part of a chemical equation called?
2H2 + O2 --> 2H2O
Reactants
Products
Yields
Chemical Equation
What is the number before a chemical formula called?
Ex: 2H2 + O2 --> 2H2O
Coefficient
Subscript
Atom
Equation
Balance this equation...
Sb2S3 + O2 --> Sb + SO2
It is balanced
Sb2S3 + 3O2 --> 2Sb + 3SO2
Sb2S3 + O2 --> 2Sb + SO2
I don't know...Oh well!
What type of reaction occurs in a hand warmer
exothermic
endothermic
Have you ever eaten sherbet sweets candy? They fizz in your mouth and your tongue feels cold. Why do you think that is?
It is an exothermic reaction
It is an endothermic reaction
It is made of ice
It is dissolving your mouth
When iron nails get rusty, heat is released. What process is this?
Exothermic
Endothermic
After you mix two substances together, a new substance forms. This is an example of:
Physical Change
Chemical Change
Which of the following is a sign of a chemical reaction?
Change in color
Change in shape
Change in size
Change in texture
What is the role of a catalyst in a chemical reaction?
It increases the temperature of the reaction
It decreases the temperature of the reaction
It speeds up the reaction without being consumed
It slows down the reaction by being consumed
In a chemical reaction, what does the term 'reactants' refer to?
The substances that are produced
The substances that are consumed
The substances that are catalysts
The substances that are inhibitors
Which type of chemical reaction involves the exchange of ions between two compounds?
Synthesis reaction
Decomposition reaction
Single replacement reaction
Double replacement reaction
What is the main difference between a chemical change and a physical change?
Chemical change involves a change in state, physical change does not
Chemical change results in new substances, physical change does not
Chemical change is reversible, physical change is not
Chemical change involves energy absorption, physical change involves energy release
