Question

Which one is an acidic anhydrates?
a. Na2O
b. MgO
c. CO2
No ideas. What does acidic anhydrates mean?

Also, from my previous post, is iron the transition element with the inner third orbital partially filled?

Thank you.

Answer 1

ok on Fe.
You mean an anhydride. An anhydride is the anhydrous form (without water) of an acid. So add water to each of the compounds and see which produces an acid. Example,
Na2O + H2O ==> NaOH (not balanced). So it can't be choice a.

Answer 2

MgO + H2O ==> Mg(OH)2 (balanced, but it's strong base, so it would not be choice b?)

CO2 + H2O ==> I don't know what's the product

Please help!
Thank you.

Answer 3

CO2 + H2O ==> H2CO3 (carbonic acid). Know what CO2 dissolved in water (to make carbonated drinks) contains? H2CO3. So CO2 is the anhydride of H2CO3.
SO2 is the anhydride of H2SO3.
SO3 is the anhydride of H2SO4.
N2O5 is the anhydride of HNO3. (The anhydride of HNO3 is NOT NO2 as many people think.) This web site has it correct.
http://www.c-f-c.com/supportdocs/nitrogen_oxi.htm

N2O3 is the anhydride of HNO2.
I know you didn't as for all this stuff but it's all free anyway. Remember this. It may come in handy someday.

Answer 4

Thank you!