07.04 Equilibrium: Hands-On Equilibrium Demonstration Lab
Equilibrium Model
Materials:



a minimum of 80 small candies, coins, or other objects
one blank sheet of paper
one notebook
Introduction:
For this lab, we will be using small items, such as candies, to represent chemical compounds undergoing a
reaction. Draw a line down the middle of a sheet of paper and label the left side of the paper “R” for
reactants and the right side “P” for products.
R
P
To represent molecules that are reactants, you will place candies on the reactant side of the paper; products
will be candies on the product side of the paper. Reactions will be represented by moving a candy from one
side of the paper to the other.
Part I
1.
2.
3.
4.
Start with 40 candies on the reactant side of the paper and zero candies on the product side.
Each round, you will be exchanging candies between R and P.
For each round, half of the candies that were on the reactant (R) side of the paper from the last
round should be moved to the product side. One-fourth of the candies that were on the product (P)
side of the paper from the last round should be moved to the reactant side. (If you end up with a
decimal for the number to exchange, round up.)
At the end of each round, count the number of candies on each side of the paper and keep track of
the numbers in a data table.
Round
Candies on R side
Candies on P
side
0
40
0
1
20
20
2
15
25
3
14
26
4
14
26
5
14
26
6
14
26
7
14
26
8
14
26
9
14
26
10
14
26
Ratio = 0.7
5.
6.
Follow the instructions in Step 3 for a total of 10 rounds.
At the end of 10 rounds, calculate the ratio (ratio = P/R) of products to reactants.
Part II
Part II will be the same procedure as Part I, except you will be starting with different initial amounts of
products and reactants.
1.
2.
3.
4.
5.
Choose a number of candies to put on the reactant side and put the rest on the products side.
For each round, half of the candies that were on the reactant (R) side of the paper from the last
round should be moved to the product side. One-fourth of the candies that were on the product (P)
side of the paper from the last round should be moved to the reactant side. (If you end up with a
decimal for the number to exchange, round up.)
At the end of each round, count the number of candies on each side of the paper and keep track of
the numbers in a data table.
Follow the instructions in Step 2 for a total of 10 rounds.
At the end of 10 rounds, calculate the ratio (ratio = P/R ) of products to reactants.
Round
Candies on R side
Candies on P
side
0
20
20
1
5
10
2
2.5
2.5
3
0.6
1.3
4
0.3
0.3
5
0.8
0.15
6
0.04
0.4
7
0.1
0.02
8
0.005
0.05
9
0.03
0.003
10
0.0008
Ratio = 1.2
0.01
Part III
Part III follows a similar procedure as Part I and Part II, except you will be adding additional candies to the
activity.
1.
2.
3.
4.
5.
Start with 40 candies on the reactant side of the paper.
For each round, half of the candies that were on the reactant (R) side of the paper from the last
round should be moved to the product side. One-fourth of the candies that were on the product (P)
side of the paper from the last round should be moved to the reactant side. (If you end up with a
decimal for the number to exchange, round up.)
At the end of each round, count the number of candies on each side of the paper and keep track of
the numbers in a data table.
After five rounds, add 40 more candies to the reactant side of the paper. Continue following the
instructions in Step 2 with this new amount of candy (total of 80 pieces of candy) for an additional
10 rounds.
At the end of 15 total rounds, calculate the ratio (ratio = P/R) of products to reactants.
Round
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Candies on R side
Candies
on P
side
Mr. Clark,
Sorry it took me so long to submit this
assignment its just that it didn’t seem
like I did it right but I think I did it
right, its kind of weird how the ratio
didn’t change I though it was going to
change.