Equilibrium Tub Activity
A. Pour approximately 3000ml of water in the large tub and place it on your left. Leave the smaller
tub empty and place it to the right. If you would like, add food coloring for fun!
B. Lay the 250 ml beakers on their side in order to draw up some water in each tub and transfer to
the other tub (yes, I know there is no water in the tub on your right but there soon will be). Do
this three times.
1. Start the fourth transfer, but STOP, and do not dump the water yet. Is the amount of
water being transferred by two beakers equal in this transfer? Explain your answer.
2. Will the amount of water in the tubs stay constant if you start transferring water
again? Explain your answer.
C. Continue transferring water back and forth between the tubs until the volume you are transfer
back and forth is equal in the two beakers, not the tubs.
1. Why are the volumes in the two beakers equal?
2. Is the volume of water in the two tubs equal?
3. How is it possible that the water you are transferring back and forth is equal but the
amount in the tubs are not equal?
4. Will the volume in the beakers stay equal if you continue to transfer the water back
and forth? Explain your answer.
5. Will the volume in each of the tubs change if you continue to transfer the water back
and forth?
6. Think of a chemical equation, what might the water in each tub represent?
7. Think of a chemical equation, what might the volume of water in the beakers
represent?
8. Which direction would you consider the “forward direction”? The “reverse
direction”?
D. Add approximately 500 ml more to the tub on the left, transfer water back and forth twice.
1. How does this affect the amount of water being transferred?
2. Which way has the reaction “shifted”?
E. Take approximately 500 ml out of the tub on the right, and then continue transferring water back
and forth.
1. How does this affect the amount of water being transferred?
2. Which way has the reaction “shifted”?
F. Start over by pouring all the water into the large tub on the left. Use the beakers again to pour
the water back and forth, but now do it faster than you did before. Continue until the volume of
water being transferred is equal.
1. Will this affect the final amount of water in tubs once the beakers are transferring
equal amounts of water?
2. What would be the advantage of pouring back and forth faster?