Project Summary:
For my science fair project, I tested water's surface tension with different solutes and at different
temperatures. To conduct this experiment, I tested how many drops of each type of water would
bead up on a penny before any spilt off the edges. This would indicate how much greater the
cohesion of the water molecules is than the adhesion to the copper. The solutes that result in
fewer drops holding on the penny indicate that there is less surface tension, and that such solute
is a surfactant.
It is hypothesized that warmer temperatures will result in less surface tension and bonding
between the water particles. This is because the Particle Theory states that as particles of a
substance gain thermal energy, they move further apart and have wealer forces of attraction to
one another, essentially making the liquid more "runny". Colder temperatures will result in more
drops of water being held on the penny, because the particles' loss of thermal enrgy will mean
that they will move less, come closer together, and have stronger forces of adhesion. When
sugar or corn syrup are added to the water, it is hypothesized that more drops of water will hold
on the penny, indicating greater surface tension. This is because these substances make liquids
more vicous and sticky, meaning water is more likely to be cohesive when sugar or corn syrup is
dissolved in it.