I'm struggling with some questions and I would really appreciate it if you could help me out and explain how to answer the following questions. Thank you for looking.
Q1
Determine the pH of the following;
(a) A solution containing 0.1 mol dm-3 formic acid (Ka = 1.8x10-4) and 2.0 mol dm-3 sodium formate.
I get this to be 4.05 but I don't understand the second part.
(b) 1 dm-3 solution of (a) after the addition of 5ml of 2.0 mol dm-3 HCL
(neglect any volume change)
Q2
Two buffer solutions were made from formic acid (Ka = 2.0x10-4 moldm-3) and sodium formate. In the first solution the concentrations of the acid and the salt were both 0.9 moldm-3 whereas in the second solution the concentrations of both constituents were 0.33 moldm-3.
(a) Calculate the pH of both solutions
(b) Which solution has the greater buffer capacity.
Q3
A buffer solution of pH 5 is required, the acid used has a Ka value of 1.8x10-5 and the if it's of use the ratio of acid to salt is 1.8:1.
If the solution is to be prepared by adding sodium hydroxide to a solution of the acid what percentage of the acid must be neutralised?
What volume of 0.1 mol l-1 NaOH is required per litre of 0.1 mol l-1 weak acid?