Wireless Conductivity Sensor

 Testing conductivity with the @pascoscientific Wireless Conductivity Sensor 

From distilled water to saturated copper sulfate — see how ion concentration changes conductivity in real-time.
Science that’s smart, fast, and wireless! #STEM #ScienceLab

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Measuring the Electrical Conductivity of Solutions Using the PASCO Wireless Sensor

Understanding the conductivity of various ionic solutions is key to exploring electrochemistry and ionic theory in both GCSE and A-Level Chemistry. In this experiment, we use the PASCO Wireless Conductivity Sensor to compare how different solutions conduct electricity, helping students visualise the role of ions in solution.

🧪 What Is Electrical Conductivity?

Electrical conductivity in a solution depends on the presence and concentration of free ions that can move and carry charge. Strong electrolytes like sodium chloride (NaCl) dissociate fully in water and produce a high number of free ions, while weak electrolytes like acetic acid only partially dissociate.

By measuring conductivity, we can assess:

• The strength of electrolytes

• The effect of concentration on conductivity

• The presence of ion mobility in complex solutions

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🧰 Equipment Needed

• PASCO Wireless Conductivity Sensor

• Erlenmeyer flask or beaker

• Distilled water (control)

• 2M Potassium Chloride (KCl)

• 2M Sodium Chloride (NaCl)

• 2M Hydrochloric Acid (HCl)

• Saturated Copper Sulfate solution (CuSO₄)

• PASCO SPARKvue software or app

• Stirring rod (optional)

• Lab gloves and goggles

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🧫 Method: Step-by-Step

1. Setup

• Open PASCO SPARKvue on your device and connect the Wireless Conductivity Sensor via Bluetooth.

• Calibrate the sensor if necessary (zero it in distilled water).

• Pour about 100 mL of each solution into separate clean beakers or flasks.

2. Testing Conductivity

For each solution:

1. Rinse the probe with distilled water and blot dry.

2. Insert the probe into the solution.

3. Wait for the reading to stabilise and record the conductivity value (in µS/cm or mS/cm).

4. Rinse and repeat with the next solution.

3. Record Your Results

Solution	Conductivity (µS/cm or mS/cm)
Distilled Water	(expect very low)
2M KCl	(expect high)
2M NaCl	(similar to KCl)
2M HCl	(very high due to H⁺ mobility)
Saturated CuSO₄	(moderate to high)

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🔬 What Are We Observing?

• Distilled water contains almost no free ions, hence very low conductivity.

• KCl and NaCl, being strong electrolytes, dissociate fully and show high conductivity.

• HCl, a strong acid, produces very mobile H⁺ ions, often resulting in even higher conductivity.

• Copper sulfate dissociates into Cu²⁺ and SO₄²⁻, both contributing to current, though its conductivity may be affected by partial precipitation.

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📊 Extension Activities

1. Effect of concentration: Dilute each solution to 1M and 0.5M and measure again.

2. Temperature effects: Use warm and cold solutions to see how ion mobility changes.

3. Compare weak acids: Test ethanoic acid and citric acid to see lower conductivity due to partial dissociation.

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🧠 Learning Outcomes

• Understand how conductivity depends on ion type and concentration.

• Recognise the differences between strong and weak electrolytes.

• Use modern digital tools (PASCO sensor and SPARKvue) for accurate data collection and analysis.

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📸 Conclusion

With the PASCO Wireless Conductivity Sensor, students can see invisible ions come to life as real data. It makes abstract chemistry tangible, measurable, and fun—especially when paired with a colourful range of solutions like in our experiment.