C) 1e- is the answer because you need that in order to balance the charges
Hello. Although it is not possible to see the video to which the question refers, we can see, in the question, that water is removed from the cylinder as a gas is added to the same cylinder. So we can see that a gas was produced in the reaction, through the displacement of water, that is, if the water starts to be removed from the cylinder, it is because the reaction is producing a gas. If the gas is not produced, water will not come out of the cylinder.
I said the equation and that was not answered
