نیٹ · کیمیا · 5 سوالات
نام: ____________________ تاریخ: ____________
Adding sodium chloride to a saturated solution of silver chloride will make the silver chloride:
A buffer contains equal concentrations of acetic acid and acetate ion. The pKa of acetic acid is 4.76. What is the pH?
What is the pH of 0.05 M sulphuric acid, taking both protons as fully ionised?
What is the value of the ionic product of water, Kw, at 25 degrees C?
An aqueous solution of ammonium chloride is:
1. C, 2. D, 3. B, 4. C, 5. D
This is the common ion effect. Extra chloride ions push the equilibrium towards the solid.
When [A-] = [HA], the log term is zero and pH = pKa = 4.76.
[H+] = 2 x 0.05 = 0.1 M, so pH = 1.
Kw = [H+][OH-] = 10^-7 x 10^-7 = 10^-14 at 25 degrees C.
It is a salt of a strong acid and a weak base. The ammonium ion releases protons in water.