Lab 3: Gas Laws and First Law

  There was a can contained a litter of water. We heated the can and then put it into the ice water. Before the experiment, our prediction was the can will implode immediately after we put it into ice water.

  First, we heated the can:

  Second, we put this hot can into ice water:

  The can was implode after we put it into ice water which matches our prediction.

  We heated another can with no water in it and put it into ice water. But the can did not change and it suctioned water this time.

  These are seven units for pressure and atmosphere pressure we found:

  We started Boyle's Law experiment by ourselves. We were using Logger Pro to drew a volume vs. pressure graph for a syringe that it's volume changing from 6cc to 20cc.

  Then we started Gay-Lussac's Law. This is our prediction graph:

  Professor started heating the flask.

  He put this flask into ice water first:

  And then he put it into hot water:

  Last, he put the flask into room temperature water:

  These are the temperature vs. pressure graphs:

  Last, we started Charles' Law:

    These are temperature vs. volume graphs:

  The ratio of kb and r (Avogadro's Number):

  This is an example question that Professor gave us to solve:

  We started a balloon experiment. We put a balloon into a vacuum chamber and drew out the air.

  As you see, the balloon is getting bigger and bigger because outside balloon pressure is decreasing when we drew out the air.

  Then we started a marshmallow vacuum chamber demo. Same condition, drew out the air from the chamber. The marshmallows were expand first and then shrink after air releasing.

  Here is another problem that Professor gave us to solve:

  In conclusion, we did many interesting experiments today. Now we know a hot can will shrink after put it into ice water. We did three different law experiments -- Boyle's Law, Gay-Lussac's Law and Charles' Law. pv=nrt is a important equation need us to remember. We also found out the Avogadro's Number 6.02* 10^23. Last, we need balloon and marshmallows' vacuum chamber demos. The balloon and marshmallows were expand when air was pulling out.

Lab 2: Thermal Expansion and Latent Heats

  When start heating up a ring and a ball, the atoms of the ring are going toward inside and outside. Both inside and outside diameters are increase even though outside atoms have more power than inside atoms. For the ball, atoms are going outside to make the ball gets bigger after heating.

  When we started heating the ring, the diameters of the ring changed, so the ball was easily pass through the ring.

  There are four variables to make the bar expand. Also, we found the unit for α.

  There was a bimetallic strip that left side is brass and right side is invar. No matter which side we heat first, it always curve to right because brass has higher coefficient of volume expansion.

  Professor put this bimetallic strip into an ice box. But it curves to left this time because the coefficient of volume expansion.

  This is the linear thermal expansion experiment. The purpose of this experiment is to find out the coefficients of linear expansion of the tube.

  The α we got is 19x10^-6 but true α value is 24x10^-6. There were a lot of uncertainities because ΔL, Lo, r, ΔT and θ are all observed by eyes. So my uncertainty of α is 19x10^-6 ± 5x10^-6 (/°C).

  There were ice in the cup. We put a heater into the cup to heat the ice for five minutes. These are the predicted graph and experimental graph of temperature changing.

  Logger Pro gave us the slope dT/dt is 0.3495 and we knew power is 293W. So we could find out the mass of water and latent heat.

  There was an example problem. We knew heat is 215kj, ice mass is 0.790kg, the temperature of ice is -5℃, we need to found the final temperature. The answer we got is -17.185℃ which is not make sense.

  There was another problem. We know mass of ice is 255g, temperature of ice is -12℃, temperature of water is 22℃, and final temperature is 0℃. We need to found the mass of water.

  One of our group member was blowing the tube to make water raise a certain height. The purpose of this experiment is to find out the pressure. The equation we used to found the pressure is ΔP=ρ(g)y.

  In today's lab, we did a lot of interesting experiments. We figure out the thermal expansion by heating a ring. Also, we heated a rod to calculate the expansion in length. We heated ice to found out the mass of ice and latent heat. And finally, we did a pressure experiment by blowed a tube to make water raise in certain height.