[kenny1999]

can anyone help me to make myself clear of these three confusing terms?

my understanding is

- base is anything that accept hydrogen ion thus something decreasing hydrogen ion's concentration, which reacts with acid (then it is a neutralization)

- alkali is a kind of base that is soluble in water. (but what does it mean by "soluble"? react with water? or forming its respective cation and anions? )

- how about "alkaline solution", does it have any difference from "alkali"?


I hope to take this chance to ask about the chemistry of Potassium Oxide / Sodium Oxide / Calcium Oxide... I know that they will form metal hydroxides when dissolved in
water, which in turns react with acid (then is a neutralization)

How about other bases like Copper(II) oxide? I think it is neither soluble in water NOR
reacting with water to form solution hydroxides.., so how does it react with acid?
will it react with acids? If it doesn't, why it is a base? I am pretty sure that it is a base...

hope I would have my concepts cleared after this post. Thanks!

[Nobby]

-base- Yes correct.

-alkali- is named from the metals of the first group. These metals react with water and form OH^- and this is an alkaline solution.

Yes: Na₂O + H₂O => 2 NaOH = 2 Na⁺ + 2 OH^-.

Copperoxide will not react with water, but acids are able to dissolve it.

CuO + H₂SO₄ => CuSO₄ + H₂O

[fledarmus]

Most chemists use "alkaline solution" in a more general sense to refer to any solution which has a pH > 7, in the same way that an "acidic solution" refers to any solution which has a pH < 7.