a. synthesis reaction c. neutralization reaction
b. ionization reaction d. decomposition reaction 2- What is the value of the self-ionization constant of water?
a. 0 c. 1.00 107
b. 1.00 1014 d. 55.4
3- Pure water contains
a. water molecules only.
b. hydronium ions only.
c. hydroxide ions only.
d. water molecules, hydronium ions, and hydroxide ions. 4- What is the concentration of OH- in pure water?
a. 1.00 107 M c. 55.4 M
b. 0.7 M d. 1.00 107 M 5- What is the pH of a neutral solution at 25°C?
a. 0 c. 7
b. 1 d. 14 …show more content…
How can the equivalence point in a titration be detected by using a pH meter?
5. Describe a method to visually detect the end point of a titration without the use of instrumentation.
PROBLEM
1. What is the pH of a solution that has a hydronium ion concentration of 8.26 10–5 M?
ANS:
pH= –log[H3O+] = –log(8.26 10–5) = 4.08
2.What is the pH of a solution with a [OH–] of 3.31 10–7 M?
ANS:
pH7.52
3.What is the pH of a 0.004 50 M HCl solution?
ANS:
pH = –log [H3O+] = –log (4.50 10–3) = 2.35
4.What is the pH of a 0.067 0 M KOH solution?
ANS:
pH 12.8
5.What is the hydronium ion concentration of a solution that has a pH of 4.12?
ANS:
[H3O] 10pH 104.12 =7.59 109 M
6.What is the hydroxide ion concentration of a solution that has a pH of 8.57?
ANS:
[HO] 3.72 106 M
7.Why is it important to choose an indicator that has an end point that closely matches the equivalence point during a titration?
ANS:
At the equivalence point of a titration there will be a quick change in the pH because the two solutions are present in chemically equivalent amounts. If an indicator has an end point at a similar pH value as the equivalence point, the indictor will turn color when the volume of the titrant contains a chemically equivalent amount as the volume of the solution of unknown