Acid-Base Unit Review Questions 1. Calculate the pH of a solution in which the [H3O+] equals: a)   1.0 M b)   0.1 M c)   0.01 M d)   1.0 X 10-7 M e)   3.0 X 10-7 M f)    4.0 X 10-10 M 2. What is the pOH, and the [H3O+1] of a 0.01 M KOH solution? 3. Calculate the [OH-1] of a solution if the pH= a)   11.00 b)   4.68 4. Calculate the [H3O+1] of a solution if the pH= a)   7.89 b)   3.54 5. Calculate the pH of a solution if it contains: a)   0.010 mole/L H3O+1 b)   0.0010 mole/L OH-1 c)   0.50 mole/L H3O+1 d)   0.25 mole/L OH-1 e)   0.015 mole/L HNO3,  assuming HNO3 is a strong acid. f)   0.22 mole/L Ba(OH)2, assuming Ba(OH)2 is a strong base. 6. Determine the pH in each of the following solutions: a)    lemon juice, [H3O+1] = 5 X 10-3 mole/L b)    milk, [H3O+1] = 3 X 10-7 mole/L c)    seawater, [H3O+1] = 3 X 10-9 mole/L 7. Benzoic acid, C6H5COOH, is an organic acid whose sodium salt, C6H5COONa, has long been used as a safe food additive to protect beverages and many foods against harmful yeasts and bacteria.  The acid is monoprotic.  Write the equation for the Ka of the acid. 8. What is the percent ionization of a 0.15 M solution of HF?  What is the pH of this ionization? 9. Periodic acid, HIO4, is an important oxidizing agent and a moderately strong acid.  In a 0.10 M solution, [H3O+1] = 3.8 X 10-2 mole/L.  Calculate the Ka and pKa for periodic acid. 10. Para-aminobenzoic acid, PABA, is a powerful sunscreening agent whose salts are used widely in suntanning and screening lotions.  The parent acid which we may symbolize as H-Paba, is a weak acid with a pKa of 4.92 at 25oC.  What will be the [H3O+1] and pH of a 0.030 M solution of this acid? 11. Ethylamine, CH3CH2NH2, has a strong pungent odour similar to that of ammonia.  Like ammonia, it is a Bronsted base.  A 0.10 M solution has a pH of 11.86.  Calculate the Kb and pKb for the ethylamine, and find the pKa for its conjugate acid, CH3CH2NH3+1 12. A sample of blood was found to have a [H3O+1] = 4.6 X 10-8 M.  Find the molar concentration of OH-1, and decide if the sample was acidic, basic, or neutral. 13. Hydrazine, N2H4, has been used as a rocket fuel.  Like ammonia, it is a Bronsted base. A 0.15 M solution has a pH of 10.70. What is the Kb and pKb for hydrazine and the pKa of its conjugate acid? 14. Quinine, an important drug in treating malaria, is a weak Bronsted base that we may represent as Qu.  At 25oC its pKb is 5.48.  To make it more stable in water, it is put into solution as its conjugate acid, which we may represent as H-QuCl.  What is the calculated pH of a 0.15 M solution of H-Qu+1? 15. Butanoic acid (butyric acid), C3H7COOH, is found in small quantities in human perspiration and is responsible for the foul odour often associated with locker rooms.  The acid is also produced when butter becomes rancid.  A 0.0010 mole/L solution of butanoic acid has a pH of 3.91 at 25oC.  Calculate the acid dissociation constant of butanoic acid.