I know that this is not a homework forum, but I want to help a student who has difficulties, which I could not solve some, in this particular subject. It would be great if anyone can help.Question: 3.9g of an element X reacts with oxygen gas to form 4.7g of an oxide X2O (X under-script O). The relative atomic mass(Ar) of X is_______?Thank you once again.
The relative atomic mass of the element is 39 (it's potassium, FWIW).3.9 g of X reacts with 0.8 g of oxygen (since 4.7 - 3.9 = 0.8)Get rid of the decimal points by multiplying by 10 on each side.This means that 39 g of X reacts with 8 g of oxygen.Handily enough, the atomic mass of oxygen is 16, which is 8 x 2.Therefore to react with 16 g (one mole) of oxygen, you need 78 g of X.For every one mole of oxygen you're using two moles of X so one mole of X weighs 39 g.The relative atomic mass of X is 39.
Wow, thank you so much EmpressFelicity!
You're very welcome Perhaps I should dredge up all my old school and uni notes and write some chemistry hubs lol.
No.... Don't write Hubs on this!!It's Far More Interesting Learning your equations in the forums!
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