If you were to come into our chemistry classroom at NTHS, you would see students as active scientists. We have actively embraced the instructional shifts that NGSS has promoted, and we are now a classroom where students learn through experimentation and exploration. By incorporating the NGSS Science and Engineering Practices, we have placed added value on the experimental process of developing questions, designing investigations, collecting and analyzing data, and making evidence-based claims. Modern technology available to students today has really evolved in recent years, and has made data collection and analysis more accessible to students than ever before.
At NTHS, we already have a number of Vernier Sensors, primarily for Environmental Science and Physics. With this EEF grant, we hope to expand our sensor collection to our chemistry students by obtaining Temperature Probes, pH Probes, Conductivity Probes and Melt Stations. All of these sensors are Go Direct Sensors, which means they will connect wirelessly via Bluetooth to our students' Chromebooks or via wired connection using USB. These kits will be purchased as part of a teacher bundle, which includes charging stations for the sensors. Here is a description each sensor from Vernier and how it would enhance our classroom:
Go Direct Temperature Sensor
Unlike a traditional thermometer, the Go Direct Temperature sensor allows students to collect real-time temperature measurements of a single instance or over a period of time. Because it is also waterproof, it is more durable than sensors that are simply water resistant.
We would use this sensor in a variety of experiments:
- Conduct endothermic and exothermic reactions.
- Investigate the freezing and melting of water in phase changes
- Measure the energy content of foods
- Monitor environmental conditions
Go Direct pH Sensor
The Go Direct pH Sensor is an important and versatile sensor for lab and field activities alike. It gives students the freedom to explore pH without the inconvenience of wires, which commonly interfere and cause solution spills. The Go Direct pH transmits live readings and captures data in real-time.
This sensor can be used in a variety of experiments:
- Conduct acid-base titrations.
- Monitor pH change during chemical reactions.
- Test the pH and alkalinity of bodies of water.
- Investigate household acids and bases.
Go Direct Conductivity Sensor
The Go Direct Conductivity Probe determines the ionic content of an aqueous solution by measuring its electrical conductivity. It features a built-in temperature sensor to simultaneously read conductivity and temperature. Automatic temperature compensation allows students to calibrate the probe in the lab and then make measurements outdoors without temperature changes affecting data. This temperature compensation can be turned off to perform conductivity studies as a function of temperature.
We would use this sensor in a variety of experiments:
- Demonstrate diffusion of ions through membranes.
- Investigate the difference between ionic and molecular compounds, strong and weak acids, or ionic compounds that yield different ratios of ions.
- Measure Total Dissolved Solids (TDS).
Go Direct Melt Station
This station teaches students the visual detection capillary method of melting point determination with the Go Direct Melt Station. It accurately measures melting temperatures of a solid (up to 260°C), and the real-time graphing provides a unique perspective of the melting process.
The wide-angle observation and magnification window, LED-lit heater block, and adjustable tilt base give students a clear view of the substance as they witness the state change. Internal cooling fans reduce the waiting time between sample testing. Also included is an important safety feature that automatically powers down the heating block after 60 minutes with no change to the control knob.
The Go Direct Melt Station can be used in a variety of experiments:
- Determine the melting temperature of an known organic solid such as aspirin, ibuprofen, or caffeine.
- Identify an unknown organic solid by its melting temperature.
- Use melting temperature to analyze reaction products.
Additionally, all of these sensors work with free software provided by Vernier, called Graphical Analysis 4. This program also works on iphones and Androids. The program is a key part of the data collection and analysis process. Some of the features the program offers to our students, using the sensors in conjunction with the program, are:
Data Collection
Collect data from multiple sensors simultaneously, either with a multiple-channel interface such as LabQuest Stream or by using multiple Go Direct sensors. Use Data Sharing to retrieve data from just about every Vernier sensor.
- Select time-based or event-based data collection, including events with entry.
- Adjust data-collection rate and duration as needed.
- Trigger time-based data collection on sensor values (iOS will not support triggering or change display units in the initial 4.0 release).
- Calibrate sensors, although most of the time this is not needed.
- Enter data manually or using the clipboard.
- Change display units on many sensors.
Data Analysis
- Display one, two, or three graphs as needed.
- Set the graph scale.
- Select what is graphed on each axis, and select line- or point-style graphs.
- Calculate descriptive statistics on all or some of your data.
- Fit lines and curves to some or all of your data.
- Define calculated columns based on sensor columns. Use this to linearize a graph, for example.
- View data in a table.
- Highlight and read values from a graph.
- Interpolate and extrapolate using graphed data.
Needless to say, these sensors really open up new possibilities for experimentation in our classrooms and embrace the goals of NGSS by using modern technologies in the experimental process. It will greatly increase our students' data analysis skills, which we also know have great crossover with Common Core Standards for Mathematics.
