Problems B
327
22. 20.00 ml of an H 3 AsO 4 solution require 40.00 ml of a 0. 1000 N NaOH solution
for titration. Calculate (a) the normality and (b) the molarity of the H 3 AsO 4
solution.
23. 35.45 ml of an NaOH solution are required to titrate a 2.0813 g sample of
benzoic acid, HC 7 H 5 O 2 . What is the normality of the NaOH solution?
24. How much of each of the following substances is needed to react completely
with 45.00 ml of 0.1000 N H 2 SO 4 ?
(a) ml of 0.2500 N NH 3
(d) mg of Al
(b) mg of NaOH
(e) mg of BaO
(c) mg of CaCO 3
25. (a) What is the normality of a eerie sulfate solution if 39.65 ml is required to
titrate a 0.3215 g sample of As 2 O 3 that is 99.70% pure?
(b) What is the molarity?
26. A 0.3217 g sample of KHC 2 O 4 requires 31.09 ml of NaOH for titration.
whereas a 0.2135 g sample requires 29.63 ml of KMnO 4 for titration. Calculate
the molarity and normality of each of these solutions.
27. A 0.0713 g sample of KIO 3 is treated with an excess of KI in acid solution, and
the I 2 that is formed requires 40.00 ml of a Na 2 S 2 O 3 solution for titration. This
titration converts the I 2 to I~, so in essence the titration is equivalent to
converting the TOj to I~, while the S 2 O|~ is being converted to S 4 Og~. Calculate the normality of the Na^Os solution.
28. A 0. 1056 g sample of KH(IO 3 ) 2 is treated as in Problem 27, and 35.75 ml of
Na 2 S 2 O 3 solution is required for the titration. A 0.5965 g sample of KH(IO 3 ) 2
requires 26.43 ml NaOH solution for titration. Calculate the normality and
molarity of these solutions.
29. What is the normality of a mixture of HO and HCIO 4 if a 25.00 ml sample
requires 35.35 ml of 0.2567 M Ba(OH) 2 for titration?
30. What volume of 12.0 N HC1 must be added to KMnO 4 in order to prepare 3.00
liters of C1 2 at 730 torr and 25.0°C?
31. (a) What volume of 6.00 M HNO 3 and what weight of copper are needed for
the production of 1.50 liters of a 0.500 M Cu(NO 3 ) 2 solution?
(b) What volume of NO, collected over water at 745 torr and 18.0°C, will also
be produced?
32. The amount of calcium in blood samples may be determined by precipitating it
as CaC 2 O 4 . This precipitate may then be dissolved in H 2 SO 4 and the C 2 Oj~
titrated with standard KMnO 4 solution. Following this procedure, 10.00 ml of
blood are diluted to 100.00 ml, and then the Ca'>+ is precipitated as CaC 2 O 4
from a 10.00 ml portion of this diluted sample. This precipitate, when washed
and dissolved in H 2 SO 4 , requires 1.53 ml of 0.00750 N KMnO 4 for titration.
How many milligrams of Ca
2+ were in the 10 ml sample of blood?
33. Any of Problems 39 through 54 in Chapter 13 would be suitable for solution by
the principles involving equivalents.
327
22. 20.00 ml of an H 3 AsO 4 solution require 40.00 ml of a 0. 1000 N NaOH solution
for titration. Calculate (a) the normality and (b) the molarity of the H 3 AsO 4
solution.
23. 35.45 ml of an NaOH solution are required to titrate a 2.0813 g sample of
benzoic acid, HC 7 H 5 O 2 . What is the normality of the NaOH solution?
24. How much of each of the following substances is needed to react completely
with 45.00 ml of 0.1000 N H 2 SO 4 ?
(a) ml of 0.2500 N NH 3
(d) mg of Al
(b) mg of NaOH
(e) mg of BaO
(c) mg of CaCO 3
25. (a) What is the normality of a eerie sulfate solution if 39.65 ml is required to
titrate a 0.3215 g sample of As 2 O 3 that is 99.70% pure?
(b) What is the molarity?
26. A 0.3217 g sample of KHC 2 O 4 requires 31.09 ml of NaOH for titration.
whereas a 0.2135 g sample requires 29.63 ml of KMnO 4 for titration. Calculate
the molarity and normality of each of these solutions.
27. A 0.0713 g sample of KIO 3 is treated with an excess of KI in acid solution, and
the I 2 that is formed requires 40.00 ml of a Na 2 S 2 O 3 solution for titration. This
titration converts the I 2 to I~, so in essence the titration is equivalent to
converting the TOj to I~, while the S 2 O|~ is being converted to S 4 Og~. Calculate the normality of the Na^Os solution.
28. A 0. 1056 g sample of KH(IO 3 ) 2 is treated as in Problem 27, and 35.75 ml of
Na 2 S 2 O 3 solution is required for the titration. A 0.5965 g sample of KH(IO 3 ) 2
requires 26.43 ml NaOH solution for titration. Calculate the normality and
molarity of these solutions.
29. What is the normality of a mixture of HO and HCIO 4 if a 25.00 ml sample
requires 35.35 ml of 0.2567 M Ba(OH) 2 for titration?
30. What volume of 12.0 N HC1 must be added to KMnO 4 in order to prepare 3.00
liters of C1 2 at 730 torr and 25.0°C?
31. (a) What volume of 6.00 M HNO 3 and what weight of copper are needed for
the production of 1.50 liters of a 0.500 M Cu(NO 3 ) 2 solution?
(b) What volume of NO, collected over water at 745 torr and 18.0°C, will also
be produced?
32. The amount of calcium in blood samples may be determined by precipitating it
as CaC 2 O 4 . This precipitate may then be dissolved in H 2 SO 4 and the C 2 Oj~
titrated with standard KMnO 4 solution. Following this procedure, 10.00 ml of
blood are diluted to 100.00 ml, and then the Ca'>+ is precipitated as CaC 2 O 4
from a 10.00 ml portion of this diluted sample. This precipitate, when washed
and dissolved in H 2 SO 4 , requires 1.53 ml of 0.00750 N KMnO 4 for titration.
How many milligrams of Ca
2+ were in the 10 ml sample of blood?
33. Any of Problems 39 through 54 in Chapter 13 would be suitable for solution by
the principles involving equivalents.