124k views
2 votes
I want to carry out a photocatalytic water spliting reaction. This reaction will generate Hydrogen and Oxygen gas in 2:1 ratio according to the following reaction -

2H₂O + energy (light) → 2H₂ + O₂
So, if I collect the produced gas over water in a test tube, should I be able to determine the volume of hydrogen gas in that mixture? From literature I came to know gas chromatography is used to determine the volume and evolution rate of hydrogen. Is that necessary for a small lab experiment?

User Thegunner
by
8.9k points

1 Answer

2 votes

Final answer:

In a small lab experiment, it is possible to estimate the volume of hydrogen gas produced in a water splitting reaction by collecting the gases and using the 2:1 stoichiometric ratio of hydrogen to oxygen. Gas chromatography is more precise but not essential for basic experiments.

Step-by-step explanation:

To determine the volume of hydrogen gas produced in the photocatalytic water splitting reaction, you can indeed collect the gases over water in a test tube. Given that the reaction produces hydrogen and oxygen in a 2:1 ratio, you can use the fact that two volumes of hydrogen gas will be produced for every volume of oxygen gas.

For a small lab experiment, it may not be necessary to use gas chromatography, which is more commonly employed for precise measurements in research.

Instead, you can visually measure the volume of gas collected or use a gas syringe to directly measure the volume of hydrogen, assuming the reaction is complete and no other gases are formed.

If you wish to confirm the identity of the gases and obtain a more accurate measurement, you could use gas chromatography. However, in a simple educational setting, understanding and applying the stoichiometry of the reaction may be sufficient to estimate the volume ratio of the produced gases and thus the volume of hydrogen gas.

User Brian Coleman
by
8.3k points