Question

Stacy reads that a 50 : 50 mixture of methanol and water is not only best for keeping a car’s radiator from freezing, but it will also take a higher temperature to make the car’s radiator boil over. Design an experiment to test this finding. You have a hot plate, water, methanol, graduated cylinders to measure volume, several glass beakers, and a thermometer at your disposal. Be sure to state your hypothesis, procedure, and any controls in your experiment. What are the dependent and independent variables? Explain the possible results if your hypothesis is supported.
(Note: Car antifreeze is a mixture of water and another substance, commonly methanol, ethylene glycol, or another low freezing-point liquid.)

Answer 1

* please do not copy-paste my answer. However, you may use it as a reference to guide you *

The claim: Using a 50-50 methanol+water mixture it will take a higher temperature to boil

As a hypothesis, we can make an if-then statement like, "If a 50-50 methanol and water mixture is added to a car's radiator, then the freezing point will be lowered and the boiling point will be raised, keeping the radiator from freezing or boiling."

For the experiment, I would recommend having a few experimental conditions where you vary the concentration of methanol vs water, and use the hot plate + thermometer to record the boiling point of the mixture. I think you could use water as the control since its boiling point is known to be 100 degrees Celcius.

Answer 2

for variables, there are two big ones to consider: the composition of the solution being tested, and the temperature. which one do you think is independent (the one that causes the other to change) and which one is the dependent?