1.Which of the following aqueous solutions are good buffer systems?
0.21 M acetic acid + 0.11 M potassium acetate
0.28 M nitric acid + 0.24 M sodium nitrate
0.32 M ammonia + 0.33 M potassium hydroxide
0.15 M sodium hydroxide + 0.30 M sodium bromide
0.38 M barium iodide + 0.22 M sodium iodide
2.A 1 liter solution contains 0.560 M nitrous acid and 0.420 M potassium nitrite.
Addition of 0.210 moles of hydrobromic acid will:
(Assume that the volume does not change upon the addition of hydrobromic acid.)
Raise the pH slightly
Lower the pH slightly
Raise the pH by several units
Lower the pH by several units
Not change the pH
Exceed the buffer capacity
3.A buffer solution is made that is 0.497M inCH3COOHand0.497M inCH3COONa .
(1) If Ka for CH3COOH is 1.80×10-5, what is the pH of the buffer solution?
(2) Write the net ionic equation for the reaction that occurs when0.147molNaOHis added to1.00L of the buffer solution.
4.An aqueous solution contains 0.22 M ammonium perchlorate.
One liter of this solution could be converted into a buffer by the addition of:
(Assume that the volume remains constant as each substance is added.)
0.22 mol NH3
0.10 mol NaOH
0.10 mol HCl
0.22 mol Ba(ClO4)2
0.22 mol HCl
5.39.4 0.305 hypochlorous acid 0.427 potassium hydroxide 18.8