Acidimetry and Alkalimetry
1. How many grams of each of the following substances constitute the gram –equivalent
wt as an acid, assuming complete neutralization, unless otherwise stated.
a) HNO3
b) KHSO4
c) H2SO3
d) H2C2O4.2H2O
e) CH3COOH
2. What is the milliequivalent wt. of each of the following substances acting as bases,
with complete neutralization in each case:
a) Ca(OH)2 b) BaO
c) KHCO3
d) Na2O
e) Fe2O3
3. A soln. of HCl has a specific gravity of 1.120 and contains 23.81% HCl by wt. How
many grams and how many milliequivalent of HCl are present in each ml of the
solution?
4. A solution containing 25.3 ml of 0.1065 N HCl is added to one containing 92.2 ml of
0.2715 M H2SO4 and 50.0 ml of 1.000 N KOH are added. Is the soln acid or alkaline?
What vol of 0.100 N acid or alkali must be added to neutralize the soln?
5. A soln of H2SO4 is found to be 0.5172 N and 39.65 ml of it are equivalent to 21.74 ml
of the standard alkali soln. What is the normality of the alkali and how many grams of
sulfamic acid (HSO2.NH2) will 1.000 ml of it neutralize/
6. How many ml of 3.00 N acid should be added to 300 ml of 0.400N acid in order for
the resulting soln. to be 0.600 N as an acid?
7. How many ml of 0.15 M H2SO4 are required to neutralize a) 30 ml of 0.30 n KOH;
b) 30.0 ml of 0.30 N Ba(OH)2
c) 20.0 ml of the solution containing 10.0 g of
KHCO2 per 100 ml?
8. Given the following data: 1.00 ml of NaOH ≈ 1.117 ml HCl. The HCl is 0.4876 N.
How much water should be added to 100 ml of the alkali to make it 0.5000 N?
9. How many grams of “available hydrogen” are shown to be present in a sample of an
organic acid if 20.0 ml of NaOH (1.00 ml ≈ 0.205 millimole of sulfamic acid,
HSO2.NH2)
are required to neutralize the acid?
10. If each ml of a soln of H2PO3 contains the equivalent of 0.5000 millimole of
dissolved P2O5, what vol. of 2.50 N NaOH would be required to react with 20.0 ml of
the acid to form HPO4 =
11. What is the normality of a soln of H2SO4 and contains 95.0 % H2SO4 by wt? How
many millimoles are contained in each ml?
12. If 30.00 g KHC2O4 . H2C2O4 .2H2O are dissolved, diluted to 1000 ml, and it is found
that 40.00 ml are neutralizes by 20.00 ml of the soln of KOH, what is the normality of the
alkali soln?
13. A mixture of 46.32 g of pure KOH and 27.64 g of pure NaOH is dissolved in water
and diluted to 1000 ml. What vol. of 1.022 N HCl is required to neutralize 50.00 ml of
the soln?
14. A mixt. weighing 1.000 g consists of equal parts by wt of Na2CO3 and K2CO3. It is
dissolved in water and 17.36 m of 1.075 N acid are added. Is the soln. acid or alkaline?
What vol. of 1.075 N acid should be added to make the solution neutral?
15. If 30.0 ml of H2SO4 are required to neutralize 25.0 ml of 0.660 N KOH soln, to what
vol. should 200 ml of the acid be diluted with water in order for the soln. to be 0.5000
N? What vol. of 1.00 N NaOH should be added to a liter of KOH in order for the
resulting solution to be 0.700 N as a base? What vol of the diluted acid will be
neutralized by 25.1 ml of the alkali mixture?
Standardization
16. In standardizing a soln. of HCl , it is found that 47.26 ml of the acid are equivalent to
1.216 g of pure Na2CO3 (methyl orange indicator) What is the normality of the acid?
17. A soln of H2SO4 is standardized against a sample which has been previously found to
contain 92.44% CaCO3 and no other basic material. The sample weighing 0.7423 g is
treated with 42.42 ml of the acid and the excess acid the requires 11.22 ml NaOH soln.
If 1.00 ml of the acid is equivalent to 0.9976 ml of the NaOH, what is the normality of
each soln?
18. A sample of Rochelle salt (KNaC4H4O6.4H2O) , after ignition to convert it to double
carbonate is titrated with H2SO4, using methyl orange as an indicator. From the
following data calc. the percentage purity of the sample:
Wt of sample = 0.9500 g, H2SO4 = 43.65 ml, NaOH used = 1.72 ml; 1.000 ml H2SO4≈
1.064 ml of 0.1321 N NaOH.
19. If 44.97 ml of a soln. of HCl are equivalent to 43.76 ml of a soln of NaOH, and if
49.14 ml of the latter will neutralize 0.2162 g of KHC2O4. H2C2O4 .2H2O , what
volume should be added to 100.0 ml of the HCl in order to make it 0.05000N?
20. In standardizing a soln of NaOH against 1.431 g potassium acid phthalate, the analyst
uses 35.50 m of the alkali and has to run back with 5.12 ml of acid (1.000 ml
≈0.003100 g Na2O). what is the normality of the NaOH soln?
Percentage purity
21. A sample of crude ammonium salt weighing 1.000 g is treated with hot KOH soln.
The NH3 liberated is collected in 50.00 ml of 0.5000 N acid, and the excess acid
requires 3.12 ml of 0.2500 N NaOH for neutralization, Calculate the percentage of
NH3 in the sample?
22. What wt . of pearl ash (impure K2CO3) should be taken for analysis in order that
a)the no. of ml of 0.5000 N acid used will be equal to one third of the percentage of
K2CO3 in the sample
b. the no. of ml of 0.5000 N acid will be one- third of the percentage of K2O in the
sample?
23. Calc. the alkaline strength of a sample of impure K2CO3 in terms of percent K2O
from the following data: Wt sample = 1.000 g , HCl used = 55.90 ml; NaOH used =
0.42 ml; 1.000 ml NaOH ≈ 0.008473 g KHC2O4.H2C2O4.2H2O ; 1.000 ml HCl ≈
2.500 ml NaOH.
24. In the analysis of a 2.000 –g sample of lime by titration with H2SO4 , what must be
the normality of the acid so that the percentage of Ca may be found by dividing the net
vol. of the acid required by 4?
25. What volume of NaOH (1.00 ml ≈0.0731 g KHC2O4 .H2O) should be added to 100
ml soln of KOH (1.00 ml contains the equivalent of 0.00471 g K2O) in order that 10.0
ml of the resulting soln will be equivalent to the nitrogen in 1.00 gram millimole of
urea , CO(NH2)2 (by method in which the N in the urea is converted to NH4HSO4 and
the ammonia subsequently evolved and titrated)?
26. A sample of crude ammonium salt weighing 1.000 g is treated with hot KOH soln.
The NH3 liberated is collected in 50.00 ml of 0.5000N acid, and the excess acid
requires 3.12 ml of 0.2500 N NaOH for neutralization. Calc. the percentage ammonia
in the sample.
27. In order to have obtained 97.60% KHC4H4O6 what volume of cream of tartar must be
taken for an analysis which involved the following data. NaOH used = 30.06 ml ;
H2SO4 used = 0.50 ml; 1.000ml H2SO4 ≈0.02550 g CaCO3; 1.000 ml H2SO4 ≈
1.020 ml NaOH?
28. .A mixture of Na2CO3 and BaCO3 weighing 0.2000 g requires 30.00 ml of 0.1000 N
acid for complete neutralization. What is the percentage component in the mixture ?
29. A mixture contains Na2CO3 , NaOH , and inert matter. A sample weighing 1.500 g
requires 28.85 ml of 0.5000 N HCl to reach a phenolphthalein end point, and so and
additional 23.85 ml to reach a methyl orange end point. What are the percentage of
Na2CO3 and NaOH?
30. From the following data calc. the percentages of Na2CO3 and NaHCO3 in a mixture
contng. These and inert material .Wt of sample = 1.100g ; vol of 0.25 N HCl required
for HpH end point = 26.40 ml; after adding an excess acid and boiling out the CO2, the
net additional vol. of 0.2500 N HCl required for the HpH end point = 40.70 ml.
31. Four different solutions are known to contain either pure NaOH, pure Na2CO3, pure
NaHCO3, or compatible mixtures of these substances.
a. Sample I gave no color with HpH
b. Sample II required the addition of 15.26 ml of standard acid to give a color change
with HpH , and an additional of 17.90 ml to give a color change with MOH.
c. a portion of Sample III was titrated with HCl until the pink of HpH disappeared and
on the addition of MOH the solution was colored pink;
d. a portion of Sample IV required 15.00 ml of standard HCl to give a color change with
HpH and an equal portion required 30.0 ml of the HCl to give a color change with
methyl orange.
32. A sample is known to consists of NaOH or NaHCO3 or Na2CO3 or possible mixtures
of these, together with inert matter. With methyl orange, a 1.10 g – sample requires
31.4 ml of HCl (of which 1.00 ml ≈ 0.0140 g CaO). With HpH, the same wt. of sample
requires 13.3 ml of the acid. Calculate the percentage of NaOH and Na2CO3 in the
original sample.
33. A 1.00. g- sample of NaOH which has been exposed to the air for some time is
dissolved in water and diluted to 500.0 ml., 100.0 ml of the solution is titrated with
0.1062 N HCl ( methyl orange indicator) and requires 38.60 ml. A second 100.0 –ml
portion is treated with excess BaCl2 , diluted to 250.0 ml and filtered., 200.0 ml of this
filtrate then require 29.62 ml of the HCl (phenolphthalein indicator). Calculate the
percentage of NaOH and of Na2CO3 in the original sample.