Innovative Uses

Osmosis Experiment

Finding examples of osmosis for the biology laboratory that can be manipulated to promote inquiry, offer relatively quick results, and are easy to set up have been hard to come by. A new osmosis investigation has been developed by Mike Collins, one of our staff biology teachers, that helps students understand this essential concept of cell homeostasis.

Using a Vernier interface, a Gas Pressure Sensor, and various concentrations of maple syrup, this key biological concept "swells" to life. This experiment is fast, easy to set up, and lends itself well to student inquiry.

Download Osmosis experiment (3.6 MB PDF)

Investigating an Acid Mixture

An interesting and challenging problem for AP Chemistry students is the investigation of a mixture. We have a great chemistry experiment available in which the student analyzes a mixture of hydrochloric acid and phosphoric acid. This lab presents the student with the task of conducting a seemingly routine acid-base titration.

However, the student must analyze the titration data to determine how much HCl and how much H₃PO₄ were mixed. As an added bonus, the student will determine the Ka₂ of H₃PO₄.

The settings on this graph show the point protectors

The settings on this graph are set at connecting line

Download Investigating an Acid Mixture (188 KB PDF)

Heat Conduction

Bernard Zalewski from Marianist Province USA sent us some information on how he uses our Go!Temp to do experiments on thermal conductivity. He uses several different metals. Here are some of his results.

What a Drag!

A customer called recently looking for ideas on aerodynamic drag experiments. This inspired us to do a little research with toy cars on the roof of a car.

We mounted two toy carts: one streamlined, and one not as aerodynamic. They were connected so that our Dual-Range Force Sensor would measure the drag force on them as we drove them along through the air. Our team of investigators included a driver, a computer operator, and someone to yell out the speedometer readings.

We collected Events with Entry data using Logger Pro. We tried to find a level stretch of road, and we used a new feature of Logger Pro 3.5 that allowed us to do a 10-second sample of the average force for each reading.

There are several sources of error, such as road vibration, changes in the road grade, wind, and the driver sometimes not holding the speed constant for the 10 seconds. Even so, the data pretty nicely show that the drag force is proportional to the square of the velocity, and that the more aerodynamic car had less drag.

Human Respiration

We all know that when you inhale, some of the oxygen gas in that breath is converted into carbon dioxide gas and then exhaled. But how much CO2 gas is produced? Would more CO₂ gas be produced if you held your breath before exhaling?

We used our CO₂ Gas Sensor on its high-range setting and a BioChamber 250 to answer these questions. First, a normal breath was exhaled through the neck of the BioChamber 250, filling the chamber. A #6 rubber stopper was placed in the top vent and a CO₂ Gas Sensor was placed in the neck, as shown.

Data collection was initiated with the results shown. This normal breath produced a CO₂ gas concentration of around 48,000 ppm. For the second run, the subject held her breath for 30 seconds prior to exhaling into the chamber. A CO₂ gas concentration of 65,000 ppm was measured.

The final run, with the subject holding her breath for 60 seconds, produced a CO₂ gas concentration of 76,000 ppm. Clearly, more CO₂ gas was being produced the longer she held her breath.

Was the oxygen gas being consumed in the same way? She’ll have to get out her Vernier Oxygen Gas Sensor and start experimenting!

Natural Bridge Caverns

Vernier recently attended the GLOBE annual conference in San Antonio, TX, where we sponsored a field trip to Natural Bridge Caverns, a limestone cave. Sixty teachers made their way through the wet, drippy tour of the caverns and collected relative humidity, temperature, and barometric pressure data along the way.

Due to the recent, heavy rains in the region, the water in the cavern rose high enough to measure the pH of the water in the aquifer. Five Vernier sensors meet GLOBE Program specifications: Relative Humidity Sensor, Stainless Steel Temperature Probe, pH Sensor, Conductivity Sensor, and Dissolved Oxygen Sensor.

Great Ideas For Physics

As usual, there have been a lot of great ideas for using our sensors in the recent science teacher journals:

• "Using a Digital Camera As a Measuring Device," by Salvador Gil, Henán D. Reisin, Eduardo E. RodrÍguez, in the September 2006 issue of American Journal of Physics, includes several ideas for doing physics by analyzing photos of water trajectories, hanging chains, and shadow lines. The analysis could be done with Logger Pro.
• Michael C. LoPresto, Henry Ford CC, Dearborn, MI, has written several interesting articles about the physics of music. He uses our microphone and Logger Pro to study the sounds. Here are some references: "Experimenting with Woodwind Instruments," in the May 2007 issue of Physics Education; "Experimenting with Musical Intervals," in the July 2003 issue of Physics Education; and "Experimenting with Brass Musical Instruments," in the July 2003 issue of Physics Education.

More Innovative Uses

Read more innovative uses such as accelerations in snowboarding, chemistry of bathtub tings, and more at www.vernier.com/innovate