Well, well, well, we have a chemistry question! What a gas-tastic topic! So, when mossy zinc and hydrochloric acid get together, they have a party and release hydrogen gas (H2). It's like a tiny gas bubble fiesta in that test tube!
Now, to confirm that it is indeed hydrogen gas, you can test it in a few Circus... oops, I mean, classic scientific ways. You can try igniting the gas with a match or a lighter. If it pops and makes a little fire show, then you've got yourself some hydrogen gas. Just be careful with those flames, don't set the lab on fire, okay? Safety first!
Another way to test the gas is by using a device called a gas syringe. You can collect the gas and measure its volume. If the gas turns out to have a volume ratio of 1:2 with the hydrochloric acid solution used, ta-da! That confirms it's hydrogen gas, my friend.
So, there you have it—hydrogen gas is the star of the show, and now you know how to test it in a safe and scientific Circus...oops, I mean, manner. Have fun experimenting, my little chemist!