Problems B
203
35 What volume of 4 00 M NaOH should be added to 5 00 liters of 0 500 M NaOH
m order to get 15 0 liters of 1 00 M NaOH on dilution with water
0
36 How would you make a standard solution that contains 10 0-y of Hg
2+ per liter
of solution
0 (Start with HgCl 2 , and use volumetric flasks, pipets, and a balance
sensitive to 0 2 mg A y is a millionth of a gram )
37 It takes 31 00 ml of 0 2500 M H 2 SO 4 to react with 48 00 ml NH 3 solution What
is the molanty of the NIV
38 How many milligrams of Na 2 CO 3 will react with 45 00 ml of 0 2500 M HC1°
39 What is the molanty of a KMnO 4 solution if 30 00 ml of it is needed for the
titration of 45 00 ml of 0 1550 M Na 2 C 2 O 4 solution
0 (See Problem 12 for the
equation )
40 What is the molanty of a cenc sulfate solution if 46 35 ml is required for the
titration of a 0 2351 g sample of Na 2 C 2 O 4 that is 99 609?: pure' The reaction is
2Ce
4+ + C 2 0 4
2 - -> 2Ce'
i+ + 2CO 2
41 A 0 2120 g sample of pure iron wire is dissolved, reduced to Fe
2+ , and titrated
by 40 00 ml KMnO 4 solution The reaction is
MnOj + 5Fe
2+ + 8H
+ -> Mn-+ + 5Fe
3+ + 4H 2 O
Find the molanty of the KMnO 4 solution
42 A 0 220 g sample of H 2 SO 4 is diluted with water and titrated by 40 0 ml of
0 100 M NaOH Find the percentage by weight of H 2 SO 4 in the sample
43 A sample of vinegar weighs 14 36 g and requires 42 45 ml of 0 2080 M NaOH
for titration Find the percentage of acetic acid, HC 2 HsO 2 , in the vinegar
44 From the following data, compute the molanty of (a) the H 2 SO 4 solution and
(b) the KOH solution
Wt of sulfamic acid, H(NH 2 )SO, - 0 2966 g
Vol of KOH to neutralize the H(NH 2 )SO, = 34 85 ml
31 08 ml of H 2 SO 4 titrates 33 64 ml of KOH
45 A crystal of calcite, CaCO 3 , is dissolved in excess HC1 and the solution boiled
to remove the CO 2 The unneutralized acid is then titrated by a base solution
that has previously been compared with the acid solution Calculate the molar
ity of (a) the acid, and (b) the base solutions
Wt of calcite - 1 9802 g
Vol of HC1 added to calcite = 45 00 ml
Vol of NaOH used in back titration = 14 43 ml
30 26 ml of acid titrates 21 56 ml of base
46 A 2 500 g sample of an ammonium salt of technical grade is treated with
concentrated NaOH and the NH 3 that is liberated is distilled and collected in
203
35 What volume of 4 00 M NaOH should be added to 5 00 liters of 0 500 M NaOH
m order to get 15 0 liters of 1 00 M NaOH on dilution with water
0
36 How would you make a standard solution that contains 10 0-y of Hg
2+ per liter
of solution
0 (Start with HgCl 2 , and use volumetric flasks, pipets, and a balance
sensitive to 0 2 mg A y is a millionth of a gram )
37 It takes 31 00 ml of 0 2500 M H 2 SO 4 to react with 48 00 ml NH 3 solution What
is the molanty of the NIV
38 How many milligrams of Na 2 CO 3 will react with 45 00 ml of 0 2500 M HC1°
39 What is the molanty of a KMnO 4 solution if 30 00 ml of it is needed for the
titration of 45 00 ml of 0 1550 M Na 2 C 2 O 4 solution
0 (See Problem 12 for the
equation )
40 What is the molanty of a cenc sulfate solution if 46 35 ml is required for the
titration of a 0 2351 g sample of Na 2 C 2 O 4 that is 99 609?: pure' The reaction is
2Ce
4+ + C 2 0 4
2 - -> 2Ce'
i+ + 2CO 2
41 A 0 2120 g sample of pure iron wire is dissolved, reduced to Fe
2+ , and titrated
by 40 00 ml KMnO 4 solution The reaction is
MnOj + 5Fe
2+ + 8H
+ -> Mn-+ + 5Fe
3+ + 4H 2 O
Find the molanty of the KMnO 4 solution
42 A 0 220 g sample of H 2 SO 4 is diluted with water and titrated by 40 0 ml of
0 100 M NaOH Find the percentage by weight of H 2 SO 4 in the sample
43 A sample of vinegar weighs 14 36 g and requires 42 45 ml of 0 2080 M NaOH
for titration Find the percentage of acetic acid, HC 2 HsO 2 , in the vinegar
44 From the following data, compute the molanty of (a) the H 2 SO 4 solution and
(b) the KOH solution
Wt of sulfamic acid, H(NH 2 )SO, - 0 2966 g
Vol of KOH to neutralize the H(NH 2 )SO, = 34 85 ml
31 08 ml of H 2 SO 4 titrates 33 64 ml of KOH
45 A crystal of calcite, CaCO 3 , is dissolved in excess HC1 and the solution boiled
to remove the CO 2 The unneutralized acid is then titrated by a base solution
that has previously been compared with the acid solution Calculate the molar
ity of (a) the acid, and (b) the base solutions
Wt of calcite - 1 9802 g
Vol of HC1 added to calcite = 45 00 ml
Vol of NaOH used in back titration = 14 43 ml
30 26 ml of acid titrates 21 56 ml of base
46 A 2 500 g sample of an ammonium salt of technical grade is treated with
concentrated NaOH and the NH 3 that is liberated is distilled and collected in