how many HCl needed to dissolve 1 grams of Al2O3.
does HCl dissolve Al2O3?
It probably reacts with it, instead.
If that's what you meant, then figure how many moles of Al2O3 you have, then check the reaction to see how many HCl it takes to react with one Al2O3.
Then you will need that many moles of HCl. Convert that back to grams if that is what is wanted.
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