A Hofmann voltameter is an electrolysis device used to demonstrate the decomposition of water into its constituent gases, hydrogen and oxygen, using an electric current. Building a modular Hofmann voltameter involves creating separate compartments for the two gases to collect, and ensuring that the setup is safe and easy to use. Here's a basic guide to building a modular Hofmann voltameter:

Materials Needed:

Transparent containers or test tubes (for gas collection)
Rubber stoppers or corks
Tubing or hoses
Electrodes (e.g., graphite or platinum)
Power source (battery or power supply)
Electrolyte solution (diluted sulfuric acid is commonly used)
Safety goggles and gloves
Wiring and connectors
Steps:

Prepare Electrodes:

Obtain two suitable electrodes, such as graphite rods or platinum wires.
Ensure that the electrodes are clean and free from any contaminants that could interfere with the electrolysis process.

Create Gas Collection Compartments:

For each gas (hydrogen and oxygen), you'll need a separate container or test tube with a rubber stopper or cork.
Drill or puncture a hole in the stopper to allow a tubing or hose to pass through. The tubing will connect the container to the electrode.

Connect Electrodes:

Insert one electrode into each gas collection compartment through the stopper.
Secure the electrode in place, ensuring a tight fit to prevent gas leakage.

Fill Containers with Electrolyte Solution:

Prepare the electrolyte solution (e.g., diluted sulfuric acid).
Fill each gas collection container with the electrolyte solution, ensuring that the electrode is submerged.

Assemble the Setup:

Connect one end of a tubing or hose to the gas collection compartment and the other end to the appropriate electrode on the power source.
Connect the other electrode to the power source as well.

Safety Measures:

Ensure good ventilation when working with gases.
Wear safety goggles and gloves to protect yourself.
Keep the setup away from open flames or sparks.

Perform Electrolysis:

Turn on the power source to initiate the electrolysis process.
Hydrogen gas will be produced at the electrode connected to the negative terminal (cathode), while oxygen gas will be produced at the electrode connected to the positive terminal (anode).

Gas Collection:

As gas bubbles form, they will rise and collect in the respective gas collection compartments.
The volume of gas collected can be measured and used to demonstrate the stoichiometric ratio of hydrogen and oxygen produced during water electrolysis.

Observations:

Observe the gas collection and the ratio of gases collected.
You should notice that twice as much hydrogen gas is collected compared to oxygen gas, in accordance with the chemical equation for water electrolysis.

Remember that safety is a top priority when working with electrolysis and gases. Ensure that your setup is well-ventilated, and take appropriate safety precautions to prevent any accidents or injuries. If you're using this as a demonstration for educational purposes, provide clear instructions to participants and supervise the process closely.  https://eastcoastpropertyservicesllc.com/recurring-house-cleaning/

Good Information 

Very nice construction.

Thank you, Doc.