When a base is disolved in water it forms..

Question

a) hydrogen ions

b) hydroxide ions

c) chloride ions

d) calcium ions

Answer 1

The description of a base goes back to the 19th century with the definition by Arrhenius, who said that a base is any substance that dissolves in water to produce hydroxide ions.

Typically bases are substances like KOH, or NaOH or Ca(OH)2.  But some bases are quite insoluble in water and may not dissolve to produce many hydroxide ions at all, like Al(OH)3.

Then there are some salts whose anions react with water to produce hydroxide ions.  These are usually the anions of weak acids.

Sodium acetate dissolves in water to make undissociated acetic acid and hydroxide ions.

C2H3O2- + HOH <==> HC2H3O2 + OH-

Answer 2

b

Answer 3

Hydroxide ions.

Answer 4

b) By definition a base is a substance that releases hydroxide ions in a solution.