Question

1) Briefly explain why the pH of 1.0*10^-2 MHCl is different from that of 1.0*10^-2M HC2H3O2? 2) Briefly explain why the pH change that resulted when you added 6M NaOH to the buffer solution was of a different magnitude than the pH change that resulted when you added aqueous NaoH to distilled water. 3) Write the chemical equation for the reaction that occurred when you added 6M NaOH to the buffer solution 4)Write the chemical equation for the reaction that occurred when you added 6M HCl to the buffer solution.

Answer 1

1) pH depends only on the H+ concentration . HCl is strong acid it gives more H+ . And Acetic acid is a weak acid and gives lesser number of H+ . Thus they both gives different pH .

2) when NaOH is added to buffer. It does not change the hydroxide ion concentration much . Because added hydroxide ion will react with the weak acid of the buffer. Thus hydroxide ion concentration remain maintain in solution . And pH does not changes to great extent.

But in distilled water , on adding hydroxide ion it increases the pH .