need help with what to do for 3.

1. A 0.5M solution of an acid was tested with the indicators used in this experiment. The colors observed were as follows: Methyl Violet: violet 115=3.7 Thvmol Blue: yellow Methvl Orange: orange 3+21.4.4 Bromcresol Green: yellow 3,55:4 What is the approximate pH of the solution? 3.23,8 Which indicators would you use to find the pH more precisely? I would hre Mxthyl orangre fince its oth bast ind ent since its workirg range lirs in the appooximated ph 2. A solution of NaCN has a pH of 10 . The CN ' ion is the anion of the weak acid HCN. Write the net ionic equation for the reaction which produces the pH of the NaCN solution. 3. The pH of a half-neutralized solution of a weak acid is 4.3. What is the dissociation constant (K) of the weak acid? 4. A solution with the volume of one liter contains 0.5 mole HC2H3O2,0.5 mole C2H3O2 - ion, and 0.5 mole Na+ion. K2 for HC2H3O2 is 1.8105. a. What is the pH of the solution? b. Is the solution a buffer? c. Why or why not? d. Write down the net ionic equation for the reaction which occurs if a little H+ion is added to the solution