Hey guys. I’m struggling to understand the concept of moles, and was hoping someone could explain it a lot easier than in previous posts. I understand that a mole of something means that there is 6.022 x 10\^23 of that something (similar to the idea of 1 dozen = 12 things), but I don’t quite understand when for example 1 mole of Nitrogen is 14g.
If 1 mole of nitrogen means that there is 6.022 x 10\^23 nitrogen atoms, how does 1 mole of nitrogen equal 14g? Is it saying that 6.022 x 10\^23 nitrogen atoms (1 mole of nitrogen) is equal to 14g, since the mass of a nitrogen atom (single nitrogen atom) would be super small, and so we use moles to convert it into a reasonable mass for easier calculations e.g. 14g?
Hope that wasn’t too confusing :S
Thanks everyone! 🙂
In: Chemistry
Nitrogen has an atomic weight of 14 (7 protons, 7 neutrons) in it’s most common isotope.
6.022 x 10^23 nitrogen atoms weighs 14 grams.
If you had some hydrogen, with an atomic weight of 1 (1 proton no neutrons), 6.022 x 10^23 hydrogen atoms would weigh 1 gram.
Why do you need to know this?
Well, let’s imagine you have 1kg of hydrogen you want to burn with oxygen. How much oxygen do you need? Well you need 2 moles of hydrogen for every mole of oxygen (because you need two hydrogen atoms for every atom of oxygen).
You have 1000/1=1000 moles of hydrogen, so you need 500 moles of oxygen. Oxygen has an atomic weight of 16 so you need 500×16=8000 grams, or 8kg.
But what if we wanted to burn an isotope of hydrogen; tritium. 1 proton, two neutrons, atomic weight 3.
You have 1000/3=333.3 moles of tritium, so you need 166.7 moles of oxygen. 166.7×16=2666.4, or 2.666kg.
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