Theories of acids and bases
2 marks · EasyThe reaction below shows how the hydroxonium ion reacts with a base.
a) Identify the base. b) Calculate how many molecules of water are formed when 1 mole of H_3O^+ reacts completely with 1 mole of OH^-.
Name the base in this reaction.
Give the number of water molecules formed (state your answer as a number).
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
(a) OH^- (hydroxide ion)
(b) 2 molecules
Also accept: hydroxide ion; OH-
Common mistakes: Giving 1 instead of 2 for water molecules
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · Correctly names OH^- as the base.
B2 (b) · 1 mark · Correctly calculates that 2 molecules of water are formed.
Worked solution
a) The base is OH^- (hydroxide ion).
b) 1 mole of H_3O^+ reacts with 1 mole of OH^- to give 2 moles of H_2O, meaning 2 molecules of water form for every pair of ions.