WorksheetsModeling Reactions
Total questions: 26
Worksheet time: 2hrs 10mins
All of the atoms present at the beginning of a chemical reaction are present at the end of a chemical equation.
True
False
What is the substance that is formed after a chemical reaction called?
product
subscript
coefficient
reactants
What are the starting materials in a reaction?
product
subscript
coefficient
reactants
What happens to atoms in a chemical reaction?
they are destroyed
they are created
they are rearranged
Does the image correctly represent the Law of Conservation of Mass?
yes
no
Does the image represent the Law of Conservation of mass?
yes
no
Select the equations that follow the Law of Conservation of Mass meaning the equation is balanced.
PICK TWO
H2 + O2 --> H2O2
CO2 --> Fe2O3
Na Cl2 --> 2NaCl
Na2 + 3H2 --> 2NH3
Why does this picture demonstrate the Law of Conservation of Mass?
the number of atoms of each element are the same on both sides
they start out separate and end up combined
the same elements are used
it doesn't demonstrate the Law of Conservation of Mass
In this model the reactant atoms differ in number from the product atoms.
True
False
H2O + CO2 → HCO + HO
In the equation shown, what are the reactant(s)?
N2 + H2
NH3
In the equation shown, what are the product(s)?
N2 + H2
NH3
The arrow symbol in a chemical equation means __.
equals
yields
less than
great than
Identify the Reactants in this equation.
A
B
Is the compound in the pink box a Reactant or a Product?
Reactant
Product
How many molecules of KNO3 are shown?
1
2
3
4
Is the following equation balanced?
Al + O2 ---> 2Al2O3
YES
NO
In this reaction, how many molecules of nitrogen (N2) are present in the reactants?
1
2
3
4
(See attached key and diagram)
In a chemical reaction known as decomposition, carbonic acid breaks down into water, and what other compound?
(Hint: count the atoms!)
Which of the following atomic models of chemical reactions correctly demonstrates the Law of Conservation of Matter?acid breaks down into water, and what other compound?
The equation
H₂O (l) → H₂O(s)
represents a:
Chemical reaction
Physical change
Neither a chemical reaction nor a physical change
Both a chemical reaction and a physical change
