pH calculation questions - table of contents

What is pH of 0.0002 M HI solution? What will be pH if 1 mL of the above was added to 999 mL of pure water?
What is pH of mixture prepared by mixing 20 mL 0.07 M NaOH and 13 mL 0.09 M HCl?
Calculate pH of 1 M solution of nitrous acid, pK_a=3.37.
Calculate pH of 0.001 M solution of benzoic acid, pK_a=4.19.
0.1 M solution of weak acid has pH=4.0. Calculate pK_a.
20 mL of 0.1 M solution of weak acid was mixed with 8 mL 0.1 M solution of NaOH. Measured pH was 5.12. Calculate pK_a.
Calculate the pH of a 0.2M solution of ammonia. K_a=5.62×10^-10.
Calculate pH of 0.01 M aniline hydrochloride. Aniline pK_b=9.4.
Calculate pH of 0.1 M potassium hydrogen oxalate. pK_a1=1.25, pK_a2=4.27.
Calculate pH of solution prepared from 0.1 mole of formic acid and 0.02 mole of NaOH diluted to 1L. pK_a=3.75.
You have 100 mL of 1 M ammonia solution (pK_a=9.25). What volume of 1 M hydrochloric acid is needed to prepare buffer with pH=9.5?
Use acetic acid and sodium acetate to prepare 0.01 M buffer solution with pH 4.50. pK_a=4.75.
What will be pH of a 100 mL buffer solution containing 0.064 M of acetic acid and 0.036 M of sodium acetate, after addition of 1 millimole of the hydrochloric acid? pK_a=4.75.