Question

12. The pH of four different solutions was measured and then small amounts of HCI (0.01 mol) were added consecutively to equal volumes of each solution. The results are given below: Initial pH Initial Solution 1 pH after first H addition 2.1 PH after second H+ addition 1.1 5.0 1.8 5.1 5.4 6.2 6.2 2 5.2 3.1 6.0 4 1.8 From the above results, explain which initial solutions are buffers and which buffer solution has the greatest buffer capacity. (8 pts)

Answer 1

12. Bubbrers are solutions that can resist the change in pH when a strong acid on base is added to them. Filom the given data, it is seen that only the initial solutions numbered 2 au 4 has showon small change it pH value atter tie tisust H+ addition while solution 1 and 3 has shown large pH change. So the initial solutions 2 and 9 ane bubbers, an Among the given better solutions, solution 2 has slowon least change in pH value even after second Ht addition. As buffer capacity is a measure of the ability of a butter solution to resist tie change in pH after addition of acid/base, butter solution (number 2) has the greatest butter capacity.