Determine the hydronium ion concentration in a solution that is 0.00042M HCL Answer in units of M.

3 answers

pH = -log (H3O^+) and since HCl is a strong acid and ionizes 100%, then
pH = -log(HCl). In very weak acid solutions it is necessary to take into account the H^+ contribution of the H^+ in water but I don't think that will be necessary in this concentration.
Determine the hydroxide ion concentration in a solution that is 0.0027 M Ca(OH)2. Answer in units of M
Ca(OH)2 ==> Ca^2+ + 2OH^-
SO, if [Ca(OH)2] = 0.0027 M then (OH^-) must be twice that. Right?