Last year in one of our Sunday School classes, one of the teachers showed us a demonstration very similar to this one. Not only did I think it was amazing from a science perspective, I also thought it was perfect for demonstrating the work of Jesus in our lives. After scouring the internet, I found this tutorial and purchased the necessary supplies…and then forgot about it until nearly a year later. :)
The experiment is simply a chemical reaction…but the demonstration is meant to show in a visual way what happens internally when we accept Jesus into our lives.
Science Experiment: Jesus Washes Our Sins Away
This object lesson is perfect for demonstrating the power of Jesus in our lives. All of us sin and we are tainted beyond repair, even when we try ourselves to fight off the “sin that so easily entangles.” It is only when we allow Jesus to come into our lives that we are cleansed and purified. Once Jesus lives in us, sin can no longer tarnish us in the eyes of God. The blood that Jesus shed on the cross washes us white as snow.
PLEASE NOTE: There are dangerous chemicals involved in this demonstration, so please use extreme caution and make sure to read the labels on each of the chemicals involved before attempting this at home (don’t let any of the chemicals come in contact with your skin, eyes, or be ingested). Do not let young children help with this demonstration.
1. Cut out 2 identical cross shapes from your sticky-backed craft foam.
2. Peel off the paper backing from the craft foam and stick the two sides together on the pole of the straw dispenser.
3. Fill the bottom of the straw dispenser with white vinegar.
4. Fill your straw dispenser about halfway with water and then add a squirt (or 5-6 drops) of your phenolphthalein.
Not pictured: Fill your other glass jar about 1/3 with water and add a splash of ammonia.
5. Use return address labels to label each jar: the jar with ammonia and water “sin” and the jar with phenolphthalein and water “you”.
For the demonstration: Pour the “sin” into the “you” jar and it will turn pink. Pour some of the pink back into the sin jar (in preparation for the next step).
Carefully place the straw dispenser lid (with the vinegar in the bottom) into the “you” jar and watch as it changes back to clear.
Attempt to pour sin into the “you” bottle with the cross still in it and it will change to clear, representing that sin can no longer taint us in the eyes of God…Jesus’ life was a sacrifice that cleanses us once and for all.
“But if we walk in the light, as he is in the light, we have fellowship with one another, and the blood of Jesus, his Son, purifies us from all sin.” -1 John 1:7
The Science Behind It: Phenolphthalein is an acid/base indicator that turns pink in the presence of bases. Ammonia is a base. When the ammonia and phenolphthalein mix, it creates a chemical reaction that turns the liquid pink. The vinegar in the base of the straw dispenser acts as an acid neutralizer and neutralizes the reaction, turning it clear again.