Question

answer the questions based on the data from the video lab.

1. for every unit of oxygen collected, how many units of hydrogen gas were collected?

1. what is the balanced equation for the burning of hydrogen in oxygen?

1. what is the reverse equation of the burning of hydrogen in oxygen?

1. in the electrolysis apparatus, where do the hydrogen ions go?

1. based on your observations of the electrolysis apparatus, where do the oxide ions go?

1. what is the mathematical ratio of the volume of oxygen created to the volume of hydrogen created?

1. how does the mathematical ratio translate to relative amounts expressed in the balanced equation?

Explanation:

1. Derived from the 2:1 H₂:O₂ ratio in water electrolysis.
2. Balanced using stoichiometric ratios for combustion.
3. Reverse of combustion is water electrolysis, balanced for atoms.
4. Hydrogen ions migrate to the negative cathode in electrolysis.
5. Oxide ions migrate to the positive anode in electrolysis.
6. From electrolysis observations, 1 unit O₂ pairs with 2 units H₂.
7. Volume ratio equals mole ratio, matching equation coefficients.

Answer:

1. 2 units
2. $\ce{2H_{2}(g) + O_{2}(g) -> 2H_{2}O(l)}$
3. $\ce{2H_{2}O(l) -> 2H_{2}(g) + O_{2}(g)}$ (electrolysis)
4. They move to the negative cathode electrode.
5. They move to the positive anode electrode.
6. 1:2 (oxygen to hydrogen)
7. The 1:2 volume ratio corresponds to the 1:2 mole ratio of $\ce{O_{2}}$ to $\ce{H_{2}}$, which matches the coefficients of these substances in the balanced water electrolysis equation.