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What metals can make hydrochloric acid release hydrogen gas?


Hi sistah from anuthah mistah! How was the mountaineering trip? Great! I used oxygen, that I had prepared on my own, from water. Look here: I split the water molecules, using electricity.

These bubbles over here are oxygen! Cool. But what are those other bubbles? Wait, don't tell me! Water is H-two-O, and you have oxygen there...

H is for... Hydrogen! Hey! That's right! H is for Hydrogen!

With electrolysis (as this method is called) you can split the water up, so you get oxygen gas on one side and hydrogen gas on the other. Just like with oxygen, the atoms are attached to each other two by two. You write it like this: H-two. Hydrogen is the most common element in the entire universe. More than nine tenths of all atoms in existence are hydrogen atoms.

But you don't find a lot of it on Earth at all, except when it's bonded with other elements, like in water. That's because hydrogen gas is so light that it disappears from the atmosphere. The Earth's gravity simply can't keep it. Wow, so the hydrogen that we've created is going to fly out into space, if we let it out? Yes, straight out in space!

I found out which of the gasses was oxygen by holding a glowing match to them, and seeing which one caught fire... Cool! Can we do like that with hydrogen? Try holding a burning match there! Okaaaay...

now I put in a burning match, and... What was that!? Jenny just confirmed that there was hydrogen in the test tube, since hydrogen reacts violently with the oxygen in the air, if it has a little help getting started. - Look at the inside of the test tube! - Look: little water droplets! So hydrogen and oxygen can smash together again with a bang and form water?! Exactly.

And hydrogen's reaction with oxygen is something we can use in fuel cells, which work rather like rechargeable batteries. In this way, hydrogen can be used as a fuel in cars. Then they don't emit any other exhaust fumes than water vapour. There are only a few cars like this on the roads today, but they are getting more common. We just have to make sure the fuel tank doesn't leak!

Excuse me, I have a question now! ... we can get hydrogen gas from water with the help of electricity. Are there any other ways to get the water to release its hydrogen? Oh, yes! Place a small piece of sodium in water, and see what happens.

Hydrogen is released when certain substances react with water. The elements you find to the left in the periodic table of elements, the alkali metals, are those that react the fastest. It's cool that a substance like water can split up like that! Are there any other substances - that can release hydrogen? - There are! Some acids, like hydrochloric acid for example, are even better than water when it comes to emitting hydrogen.

Hydrochloric acid consists of hydrogen and chlorine, but the hydrogen atoms aren't bound as hard as in a water molecule. That's why some substances that don't react with water, like iron and zinc, can still be dissolved and release hydrogen from hydrochloric acid. The metals that don't dissolve in hydrochloric acid are called noble metals, like gold and silver. Okay! I have ONE MORE QUESTION.

What can we use hydrogen for? Other than have it react with oxygen to release energy? Hydrogen is mostly used in the chemical industry to form new substances. More than half of all hydrogen gas produced is used to make fertilizer. And maybe you have eaten margarine some time?

That's made from liquid vegetable oils. With hydrogen, you can change their chemical composition and make them solidify. Check this out! I just thought of another thing to use hydrogen for. - Party balloons! - Yes, hydrogen gas is the lightest substance, so it can make balloons rise. But if you want to use it in an airship you must be very careful, so that it doesn't catch fire.