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HW 12.17

Posted: Fri Jun 08, 2018 5:03 pm
by Joanna Pham - 2D
For this problem, we are being asked to state if the following oxides are acidic, basic, or amphoteric of BaO, SO3, As2O3, and Bi2O3.

How do you determine if it’s acidic, basic, or amphoteic if we’re just given the molecule? Do we just draw out the Lewis structure and see from there?

Re: HW 12.17  [ENDORSED]

Posted: Sun Jun 10, 2018 4:06 pm
by Chem_Mod
Look at the element placement in the periodic table.

Remember in class I discussed the metal oxides like BaO are basic, and the nonmetal oxides like SO3 are acidic.
We also discussed the diagonal band of elements between the metals and nonmetals that form amphoteric oxides.

Look at the table in your textbook to see which elements for basic, acidic, or amphoteric oxides.

Re: HW 12.17

Posted: Sun Jun 10, 2018 4:12 pm
by Priscilla Okaiteye
For acidic oxides, they react with water to form a Bronsted acid, basic oxides will form a hydroxide when reacting with water, and amphoteric substances are just thing that has both acidic and basic character, like H2O.

These are just ways you can identify them, but I'm pretty sure there are more.

Re: HW 12.17

Posted: Tue Jun 12, 2018 6:49 pm
by Emma Leshan 1B
I don't understand why SO3 is acidic. I don't see why it would accept protons. Doesn't it already have -2 charge?

Re: HW 12.17

Posted: Tue Jun 12, 2018 9:43 pm
by Andrew Evans - 1G
SO3 is acidic because the nonmetal will not "let go" of the Oxygen in the same way a metal oxide would. Instead the whole molecule reacts with water to form a molecule that can then donate an H+ proton into the solution.

SO3 + H2O -> H2SO4

So basically the two molecules merge. Now the H2SO4 molecule is a strong acid and will lose a proton, making the surrounding solution acidic:

H2SO4 + H2O -> HSO4- + H3O+

-Andrew Evans
Section 1G