I tried to extract hydrogen for my kid's birthday, by mixing caustic soda with water and aluminum foil (mixed in a glass bottle). A lot of heat and (hopefully)hydrogen was released.
However, within 2-3 hours, the balloons started losing altitude and began falling down. I supposed it was caused by losing the gas slowly.
But when I tried to burn the ballon the next day it did not create the pop sound for the hydrogen test.
Please excuse me if this is a naive question. I'm curious since this is the first time I'm dealing with hydrogen and balloons. I attempted this for almost 4-5 time. And every time the balloon stopped flying within 2-3 hours. All other balloons filled with air did not lose gas.
I want to know what happens to the gas. Does it go out? Is it some sort of diffusion?