Download Mole Concept - Shailendra Kumar Chemistry

PHYSICAL CHEMISTRY
By:- Shailendra kumar
H.O. :- OPP. KHUDA BAKSH LIBRARY, ASHOK RAJPATH, PATNA - 4
B.O.: House No. 5A/65, Opp. Mahual Kothi, Alpana Market, Patna
CONFIDENCE BUILDING TEST - 1
1.
Convert 0.5 M KMnO4 in gm/liter ................................
(Mol. wt of KMnO4 = 158)
2.
Calculate no. of DOZEN in 60 mango.
3.
Calculate no. of mol of Na+ in 6.023 × 1025 ion Na+.
4.
Calculate no. of H+ per ml in 10–5 M H2SO4.
5.
Calculate no. of H+ per ml in 10–5 M HCl.
6.
Calculate
molarity
× 10 –2
1×
M
H 2 SO 4 ,
×10–2 M HNO3 mixed.
1×
7.
In the above problem
mol of H+ in resulting solution.
8.
Calculate no. of molecule of CO2 in 440 amu CO2.
9.
Calculate
gm.
10.
18
gm
C 6 H 12 O 6
25
ml
of
this
atom in final solution.
11.
wt.
in
resulting
of
H+
× 10 –2
100
ml
of
1×
of
(Q.
one
dissolved
solution
N
=
molecule
6)
solution
when
M
HCl
and
calculate
of
CO 2 ,
no.
of
H+
C 6 H 12 O 6
in
water
and
make
250
diluted
ten
times.
Calculate
100
100
and
and
ml
ml
of
of
no.
of
CO
in
ml
solution.
no.
of
C
Match the following choosing one item from column [X] and the
appropriate item from column [y]
[X]
wt [Y]
× 1000
(a) Dilution
(i)
Mol. wt
× 1000
Mol. wt × V (ml)
wt
(b) No. of milli mol
(ii)
(c) Molarity
(iii) MV = Constant
(d) No. of mol
(iv)
(e) No. of DOZEN
(v)
(f) amu
(g) Wt. of one mol C6H12O6
(vi) 180 gm
(vii) 1.66 ×10–24 gm
No. of particle × DOZEN
12 particle
No. of molecule
NA molecule
× mol
CONFIDENCE BUILDING TEST - 2
1.
Give the number of moles of each element present in 1.0
mol of each of the following substances:
(a) NH3
(b) N2H4
(c) (NH4)2Cr2O7
(d) CoCl2 . 6H2O
(d) How many molecules are in 5.0 mg of
aspartame?
(e) How many atoms of nitrogen are in 1.2 g of
aspartame?
2.
How many atoms of each element are present in 1.0 mol
of each of the substances in Ques. no 1?
(f) What is the mass in grams of 1.0 × 10 9
molecules of aspartame?
3.
How many grams of each element are present in 1.0 mol
of the substances in Question no. 1?
(g) What is the mass in grams of one molecule of
aspartame?
4.
How many moles of each element are present in 1.0 mol
of the substances in Question no. 1?
11. The molecular formula of acetylsalicylic acid (aspirin),
one of the most commonly used pain relievers, is C9H8O4.
5.
How many atoms of each element are present in 1.0 mol
of the substances in Question no. 1?
6.
Determine the mass in grams of :
(a) 3.00 × 1020 N2 molecules
(b) 3.00 × 10–3 mol of N2
(c) 1.5 × 102 mol of N2
(d) a single N2 molecule
7.
8.
9.
Aluminum metal is produced by passing an electric
current through a solution of aluminum oxide (Al2O3)
dissolved in molten cryolite (Na3AlF6). Calculate the
molecular weights of Al2O3 and Na3AlF6.
Ascorbic acid, or vitamin C (C6H8O6), is an essential
vitamin. It cannot be stored by the body and must be
present on the diet. What is the molecular weight of
ascorbic acid? Vitamin C tablets are often taken as a
dietary supplement. If a typical tablet contains 500.0 mg
of vitamin C, how many moles and how many molecules
of vitamin C does it contain?
How many moles are represented by each of these
samples?
(a) 100 molecules (exaclty) of H2O
(b) 100.0 g of H2O
(c) 500 atoms (exactly) of Fe
(d) 500.0 g of Fe
(a) Calculate the molecular weight of aspirin.
(b) A typical aspirin tablet contains 500 mg of C9H8O4.
How many moles of C9H8O4 molecules and how many
molecules of acetyl salicylic acid are in a 500-mg tablet?
12. Chloral hydrate (C2H3Cl3O2) is a drug that is used as
sedative and hypnotic.
(a) Calculate the molecular weight of chloral
hydrate.
(b) How many moles of C 2H 3Cl3O2 molecules are
in 500.0 g of chloral hydrate?
(c) What is the mass in grams of 2.0 × 10–2 mol of
chloral hydrate?
(d) How many chlorine atoms are in 5.0 g of chloral
hydrate?
(e) What mass of chloral hydrate would contain
1.0 g of Cl?
(f) What is the mass of exactly 500 molecules of
chloral hydrate?
13. Calculate the molecular weight of each of the following
substances:
(a)
CuCl 2 .6H 2 O (The .6H 2 O indicates
presence of six water molecules.)
(b) NaBrO3
(c) (C 2F 4)500 (the polymer Teflon), which is made
of the unit :
F
(e) 150 molecules (exactly) of O2
(f) 150.0 g of Fe2O3
10. Aspartame is an artificial sweetener that is 160 times
sweeter than sucrose (table sugar) when dissolved in
water. It is marked as Nutra-Sweet. The molecular formula
of aspartame is C14H18N2O5.
(a) Calculate the moleculer weight of aspartame.
(b) How many moles of molecules are in 10.0 g of
aspartame?
(c) What is the mass in grams of 1.56 mol of
aspartame.
the
F
–C – C–
F
F
14. How many atoms of carbon are present in 1.0 g of each
of the following?
(a) CH4O
(b) CH3CO2H
(c) Na2CO3
15. Vitamin B12, cyanocobalamin, is essential for human
nutrition. It is concentrated in animal tissue but not in
higher plants. Although nutritional requirements for the
vitamin are quite low, people who abstain completely
from animal products may develop a deficiency anemia.
Cyanocobalamin is the form used in vitamin supplements.
It contains 4.34% cobalt by mass. Calculate the molecular
weight (molar mass) of cyanocobalamin assuming there
is one atom of cobalt in every molecule of
cyanocobalamin.
16. Hemoglobin is the protein that transports oxygen in
mammals. Hemoglobin is 0.342% Fe by mass, and each
hemoglobin molecules contains four iron atoms.
Calculate the molecular weight (molar mass) of
hemoglobin.
17. A student prepares a solution by dissolving 4.75 g of
solid KOH in enough water to make 275 mL of solution.
(a) Calculate the molarities of the major ionic species
present. (b) Calculate the molarities of the major ionic
species present if 25.00 mL of this solution is added to a
100-mL volumetric flask and water us added to the mark.
18. What species are present in solution when the following
compounds are dissolved in water? (a) ammonium
sulfate; (b) Carbon dioxide: (c) sodium fluoride; (d)
potassium carbonate; (e) sodium hydrogensulfate; and
(f) chlorine.
19. Aqueous solutions of potassium permanganate are often
used in general chemistry laboratories. A laboratory
instructor weighed out 474.1 g of KMnO4, added the
solid to a 2.00-L volumetric flask, and filled to the mark
with water. A 50.00-mL sample was removed from the
volumentric flask and mixed with enough water to make
1.500 L of solution. What was the final molarity of the
KMnO4 solution?
20. Vitamin B12 is a large molecule called cobalamin. There is
one atom of cobalt in each molecule of vitamin B12, and
the mass percent of cobalt is 4.34%. Calculate the molar
mass of cobalamin.
21. A worker in a biochemistry laboratory needed a solution
that was 0.30 M in sodium acetate (NaCH3CO2) and 0.15
M in acetic acid (CH3CO2H). On hand were stock
solutions of 5.0 M solution acetate and 5.0 M acetic
acid. Describe how the worker prepared 1.5 L of the
desired solution.
22. The density of pure water is 1.0 g/mL. Calculate the molar
concentration of water molecules in pure water.
23. Plants can be badly damaged by solutions that are highly
concentrated. A biochemist friend of the urban gardener
recommends against using fertilizer solution that are
greater than 1.0 mM (1.0 × 10–3 M) in total nitrogen. If
the gardener wants to prepare 750 mL of 1.0 mM fertilizer
solution, how many milliliters of the stock solution will
be need to make the desired solution?
24. When aqueous solutions are used for intravenous
infusions, it is essential that the molarity of the solution
match the molarity of blood. Blood is approximately 0.31
M, so a solution of sodium chloride for infusion, called
saline, must have a concentration of 0.155 M. Calculate
the mass of NaCl that solution be used to prepare 5.00 L
of a 1.00 M stock solution, and then calculate how many
milliliters of the resulting stock solution must be diluted
to give 455 mL of 0.155 M solution for infusion.
Solution
1. (a)
(b)
(c)
(d)
2. (a)
(b)
(c)
(d)
3. (a)
(c)
(d)
4. (a)
(b)
(c)
(d)
5. (a)
(b)
(c)
(d)
1.0 mol N; 3.0 mol H;
2.0 mol N; 4.0 mol H;
2.0 mol N; 8.0 mol H; 2.0 mol Cr; 7.0 mol O;
1.0 mol Co; 2.0 mol Cl; 12 mol H; 6.0 mol O;
6.0 × 1023 atoms N; 18 × 1024 atoms H;
1.2 × 1024 atoms N; 2.4 × 1024 atoms H;
1.2×1024 atoms N; 48×1024 atoms H;1.2×1024 atoms Cr; 4.2×1024 at
oms O;
6.0 × 1023 atoms Co; 1.2 × 1024 atoms Cl; 7.2 × 1024 atoms H;3.6 × 1024
atoms O;
14 g N; 3.0 g H;
(b) 28 g N; 4.0 g H;
28 g N; 8.0 g H; 1.0 × 102 g Cr; 1.1 × 102 g O;
59 g Co; 71 g Cl; 12 g H; 96 g O;
5.9 × 10–2 mol N; 1.8 × 10–1 mol H;
6.3 × 10–2 mol N; 1.3 × 10–1 mol H;
7.9 × 10–3 mol N; 3.2 × 10–2 mol H; 7.9 × 10–3 mol Cr;
2.8 × 10–2 mol O;
× 10–3 mol Cl; 5.0 × 10–2 mol H; 2.5 × 10–2 mol O;
× 10–3 mol Co; 8.4×
4.2×
3.5 × 1022 atoms N; 1.1 × 1023 atoms H;
3.8 × 1022 atoms N; 7.5 × 1022 atoms H;
4.8 × 1021 atoms N; 1.9 × 1022 atoms H; 4.8 × 1021 atoms Cr; 1.7 × 1022
atoms O;
2.5 × 1021 atoms Co; 5.1 × 1021 atoms Cl; 3.0 × 1022 atoms H; 1.5 ×
1022 atoms O;
6. (a) 1.40 × 10–2 g N2; (b) 8.40 × 10–2 g N2; (c) 4.2 × 103 g N2;
(d) 4.65 × 10–23 g N2;
7.
Al2O3, 102.0 g/mol; Na3AlF6; 210.0 g/mol;
8.
2.841 × 10–3 mol; 1.711 × 1021 molecules;
9. (a) 1.66 × 10–22 mol (100 is exact) (b) 5.549 mol;
(c) 8.30 × 10–22 mol (500 is exact)
(d) 8.953 mol;
(e) 2.49 × 10–22 mol (150 is exact)
(f) 0.9393 mol;
10.(a) 294 g/mol
(b) 3.40 × 10–2 mol;
(c) 459 g;
(d) 1.0 × 1019 molecules
(e) 4.9 × 1021 atoms of nitrogen;
(f) 4.9 × 10–13 g or 490 fg;
(g) 4.88 × 10–13 g/molecule
11. (a) 180.0 g/mol; (b) 3 × 10–3 mol; 2 × 1021 molecules;
12.(a) 165.4 g/mol; (b) 3.023 mol; (c) 3.3 g (d) 5.5 × 1022 atoms of chlorine
(e) 1.6 g chloral hydrate (f) 1.373 × 10–19 g
13.(a) 242.5 g/mol (b) 150.9 g /mol
(c) 5.0 × 104 g/mol
at
oms (c) 5.7 × 1021 atoms
14.(a) 1.9 × 1022 atoms of C; (b) 2.0 × 1022
15.
1360 g/ mol
16.
65497 g/mol
–
–
17. (a) [K+] = [OH ] = 0.308 M
(b) [K+] = [OH ] = 0.077 M
18. (a) H2O, NH4+, SO4–2 (b)H2O,CO2
(c) H2O, Na+, F– (d) H2O, K+, CO 3–2 ,
–
19.
20.
21.
22.
23.
24.
(e) H2O, Na+, HSO4 , (f) H2O, Cl2
5 × 10–2 M
1.36 × 103 g/mol
Mix 0.090 L of sodium acetate solution, 0.045 liter of acetic acid
solution and enough water to make the final volume 1.5 liter
55.55 M
1.2 mL
292 g , 7.5 mL
CHEMISTRY
By:- Shailendra Kumar
H.O. :- OPP. KHUDA BAKSH LIBRARY, ASHOK RAJPATH, PATNA - 4
B.O.: House No. 5A/65, Opp. Mahual Kothi, Alpana Market, Patna
CONFIDENCE BUILDING TEST-3
1. Which of the following is correct ?
(a) 1 L = 1 dm3
(b) 1 L = 10 dm3
(c) 10 L = 1 dm3
(d) 1 L = 1 m3
2. 5.6 litres of a gas at N.T.P are found to have a
mass of 11 g. The molecular mass of the gas is
(a) 22
(b) 44
(c) 88
(d) 32
3. How many atoms are present in a mole of H2SO4?
(a) 3 × 6.02 × 1023
(b) 5 × 6.02 × 1023
(c) 6 × 6.02 × 1023
(d) 7 × 6.02 × 1023
4. The total number of electrons present in 18 ml of
water (density of water is 1 g ml–1) is
(a) 6.02 × 1023
(b) 6.02 × 1026
(c) 6.02 × 1024
(c) 6.02 × 1025
5. If 1021 molecules are removed from 200 mg of CO2,
then the number of moles of CO2 left are
(a) 2.88 × 10–3
(b) 28.8 × 10–3
(c) 0. 288 × 10–3
(d) 6.02 × 10–2
6. Number of molecules in 100 ml of each of O2, NH3
and CO2 at STP are
(a) in the order CO2 < O2 < NH3
(b) in the order NH3 < O2 < CO2
(c) the same
(d) NH3 = CO2 < O2
7. A gas is found to have the formula (CO)x. Its V.D.is
70. The value of x must be
(a) 7
(b) 4
(c) 5
(d) 6
8. 1 mol of CH4 contains
(a) 6.02 × 1023atoms of H
(b) 4 g atoms of hydrogen
(c) 1.81 × 1023molecules of CH4
(d) 3.0 g of carbon
9. Which one of the following pairs of gases contains
the same number of molecules ?
(a) 16 g of O2 and 14 g of N2
(b) 8 g of O2 and 22 g of CO2
(c) 28 g of N2 and 22 g of CO2
(d) 32 g of O2 and 32 g of N2
10. The number of water molecules in 1 litre of water
is
(a) 18
(b) 18 × 1000
(d) 55.55 NA
(c) NA
11. The number of oxygen atoms in 4.4 g of CO2 is
approx.
(a) 1.2 × 1023
(b) 6 × 1022
(c) 6 × 1023
(d) 12 × 1023
12. A 5 molar solution of H2SO4 is diluted from be
1 litre to a volume of 10 litres, the normality of the
solution will be:
(a) 1 N
(b) 0.1 N
(c) 5 N
(d) 0.5 N
13. The number of moles of BaCO3 which contains 1.5
moles of oxygen atoms is
(a) 0.5
(b) 1
(c) 3
(d) 6.02 × 1023
14. The total number of protons in 10 g of calcium
carbonate is (N0 = 6.023 × 1023)
(a) 1.5057 × 1024
(b) 2.0478 × 1024
(c) 3.0115 × 1024
(d) 4.0956 × 1024
15. If NA is Avogadro’s number then number of valence
electrons in 4.2 g of nitride ions (N3–) is
(a) 2.4 NA
(b) 4.2 NA
(c) 1.6 NA
(d) 3.2 NA
16. Haemoglobin contains 0.33% of iron by weight. The
molecular weight of haemoglobin is approximately
67200. The knumber of iron atoms (at. wt. of
Fe = 56) present in one molecule of haemoglobin is
(a) 6
(b) 1
(c) 4
(d) 2
17. 250 ml of a sodium carbonate solution contains 2.65
grams of Na2CO3. If 10 ml of this solution is diluted
to one litre, what is the concentration of the resultant
solution ? (mol. wt. of Na2CO3 = 106)
(a) 0.1 M
(b) 0.001 M
(c) 0.01 M
(d) 10–4 M
18. The number of moles of SO2Cl2 in 13.5 g is
(a) 0.1
(b) 0.2
(c) 0.3
(d) 0.4
19. The number of atoms in 4.25 g of NH 3 is
approximately
(a) 1 × 1023
(b) 1.5 1023
(c) 2 × 1023
(d) 6 × 1023
20. Which has maximum molecules ?
(b) 2 g H2
(a) 7 g N2
(c) 16 g NO2
(d) 16 g O2
21. A compound has haemoglobin like structure. It has
one Fe. It contains 4.6% of Fe. The approximate
molecular mass is
(a) 100 g mol–1
(b) 1200 g mol–1
(c) 1400 g mol–1
(d) 1600 g mol–1
22. Which has maximum number of atoms ?
(a) 24 g of C (12)
(b) 56 g of Fe (56)
(c) 27 g Al (27)
(d) 108 g of Ag (108).
23. Calculate kb of Cl– (Assume ka of HCl is 107)
(a) 10–7
(b) 1014
(c) 1021
(d) 10–21
24. Concentration of H+ in 10–7 M HCl solution is
approximetely
(a) 2 × 10–7 M
(b) 10–7 M
–14
(c) 10 M
(d) 10–8 M
25. Which two of the following solution contains equal
pH.
(1) 50 ml of 0.10 M HCl + 25 ml H2O
(2) 50 ml of 0.10 M HCl + 50 ml H2O
(3) 50 ml of 0.10 M H2SO4 + 25 ml H2O
(4) 25 ml of 0.10 M H2SO4 + 50 ml H2O
(a) (1) and (4)
(b) (1) and (3)
(c) (1) and (2)
(d) (2) and (3)
26. If 40 ml of 1.6 M HCl and 60 ml of 2.0 M NaOH
are mixed, What are the molar concentrations of
Na +.
(a) 0.640 M
(b) 1.2 M
(c) 0.560 M
(d) 0.65 M
27. Calculate no of millimol of CO2 in 5.6 liter CO2 at
S.T.P
(a) 200
(b) 250
(c) 1000
(d) 100
28. Kb of acetate ion (CH3COO–) is ......
Ka of acetic acid is 1.8 × 10-5
(a) 1.8 × 109
(b) 1.8 × 10+5
(c) 5.6 × 104
(d) 5.6 × 10–10
29. Predict the nature of solution is Acidic, Basic or
Neutral in following soution of ions.
(b) CH3COO–
(a) Na+
(c) Cl–
(d) NH4+
(e) K+
(f) NO3–
30. Calculate weight of oxygen atom in 6.023 × 1024
atom oxygen
(a) 16 gm
(b) 32 gm
(c) 160 gm
(d) 1600 gm
31. Which of the following reaction explain the basic
nature of sodium acetate (CH3COONa)
CH3COOH + NaOH
(a) CH3COONa + H2O
Week acid
Strong base
100%
(b) CH3COONa
CH3COO + Na+
Na+ + H2O
No reaction (No Hydrolysis)
–
–
CH3COOH+OH
CH3 – COO + H2O
(c) Na+ + H2O
NaOH + H2
–
+
(d) CH3COO + H
CH 3COOH
32. 9.8 gm H 2SO 4 dissolved in water and make
250 mL solution, molarity of 25 ml of this solution is
(a) 0.004 M
(b) 0.04 M
(c) 0.4 M
(d) 0.024 M
33.Which of the following is correct representation of
KNH . (Assume pure NH3 self ionizes into NH4+
3
and NH2–)
(a) KNH
=
[NH3] [NH2–]
3
(b) KNH
(c) KNH
3
3
=
[NH4+] [NH2–]
=
[NH2–] [NH2–]
(d) KNH
=
[NH3] [NH3]
3
34. What is the total concentration of Cl– in a mixture
that is 0.20 M MgCl2, 0.30 M NaCl and 0.40 M
AlCl3.
(a) 0.30 M
(b) 0.90 M
(c) 2.80 M
(d) 1.90 M
35. How many moles of Ca(OH)2 are present in 350
ml of 0.010 M aqueous solution of Ca(OH)2
(a) 35
(b) 3.5
(c) 0.0035
(d) 0.035
36. In problem (35) what is the molar concentration of
Hydroxide ion
(a) Zero
(b) 0.010 M
(c) 0.021 M
(d) 0.0070 M
37. What volume of 0.040 M aqueous HCl solution
would be required to entirely neutralize the solution
in 350 ml of 0.010 M aqueous solution of Ca(OH)2.
(a) 175 ml
(b) 75 ml
(b) 350 ml
(d) 700 ml
A N S W E R S
1.
(a)
2.
(b)
3.
(d)
4.
(c)
5.
(a)
6.
(c)
7.
(c)
8.
(b)
9.
(a)
10.
(d)
11.
(a)
12.
(a)
13.
(a)
14.
(c)
15.
(a)
16.
(c)
17.
(b)
18.
(a)
19.
(d)
20.
(b)
21.
(b)
22.
(a)
23.
(d)
24.
(a)
25.
(a)
26.
(b)
27.
(b)
28.
(d)
29.
(a) Neutral
(b) Basic
30.
(c)
31.
(b)
35.
(c)
36.
(d)
(c) Neutral
(d) Acidic
(e) Neutral
32.
(c)
33.
37.
(a)
(b)
(f) Neutral
34.
(d)
CHEMISTRY
By:- Shailendra Kumar
H.O. : Opp. Khuda Baksh Library, Ashok RajPath, Patna -4
B.O.: House No. 5A/65, Opp. Mahual Kothi, Alpana Market, Patna
Confidence Building Test - 4
1. How many moles of calcium hydroxide are present
in 350 mL of a 0.010 M aqueous solution of Ca(OH)2?
concentration, 15.75 mL of it are required to reach
the neturalization point in a reaction with 0.3500
grams of KHP (MW = 204.2 g/mol). What is the molar
concentration of NaOH?
(a) 35
(b) 3.5
(a) 0.1088 M
(b) 1.11 × 10–4 M
(c) 0.010
(d) 0.0035
(c) 0.022 M
(e) 10.0
2. In Problem 1, what is the molar concentrration of
the hydroxide ion?
(a) zero
(b) 0.010 M
(c) 0.021 M
(d) 0.0050 M
(e) 0.0070 M
3. What volume of 0.040 M aqueous HCl solution would
be required to entirely neutralize the solution in
Problem 1?
(a) 43.75 mL
(b) 87.5 mL
(c) 175 mL
(d) 350 mL
(e) 700 mL
4. Suppose 100 mL of 0.020 M aqueous H3PO4 are
added to the solution in Problem 1. Assuming the
olumes are additive, what are the concentrations of
OH– species present after reaction?
(a) zero
(b) 0.0022 M
(c) 0.0011 M
(d) 0.005 M
(e) 1.11×
×10–6
5. Which of the following would be a satisfactory primary
standard for titrating a solution of HCl (aq)?
(a) NaOH
(b) Na2CO3
(c) KHP
(d) HNO3
(e) HAc
6. In standardizing a solution of NaOH (aq) of unknown
(d) 22.2 M
7.
Identify the INCORRECT statement:
(a) One equovalent of a substance has 1 mole of
reactive capability
(b) The equivalent weight of a substance is the grams
of that substance in one equivalent
(c) One mole of HCl is also one equivalent of HCl
(d) An equivalent of acid exactly neutralizes an
equivalent of base
(e) The Normality of a solution is the number of
equivalents per mole of that solution
8. Identify the INCORRECT statement:
(a) 24.5 grams of H2SO4 is 1/2 of an equivalent of
H2SO4
(b) A 0.100 N solution of Ca(OH)2 is 0.050 M
(c) The equivalent weight of Ca(OH)2 is 74 g/equiv.
(d) A 6.0 M solution of H3PO4 is 18.0 N
9. What is the normality of an H2SO4 solution if
10.0 mL of it exactly neutralizes 100.0 mL of 2.0 N
sodium hydroxide solution?
(a) 0.10 N
(b) 0.20 N
(c) 10.0 N
(d) 20.0 N
10. What is the H3O+ concentration in 1.0 M NaOH?
(a) 1.0 M
(b) 1.0 × 10–14 M
(c) 1.0 × 1014 M
(d) 1.0 × 10–7 M
11. What is the OH– concentration in a neutral aqueous
solution?
(a) exactly zero
(b) 1.0 × 10–14 M
19. What is the NH4+ concentration of the solution in
Problem 18?
(c) 7.0 M
(a) 6.0 M
(d) 1.0 M
(e) 1.0 × 10
–7
M
12. A particular vinegar solution has a H3O+ concentration
of 0.015 M. What is the pH the solution
(a) 1.8
(b) 0.0104 M
(c) 1.8 × 10–4 M
(d) 1.8 × 10–4 M
20. HNO2 has a pKa = 3.35 and HOCl has a pKa = 7.45.
Which is the stronger acid?
(b) 1.8
(a) HNO2
(c) 0.015 M
(b) HOCl
(d) 3.3
(e) 3.3
13. What is the pOH of the solution in problem 12?
(a) 10.7
21. Based on the information given in Problem 20, what
is the Ka of HNO2?
(a) 5.25 × 10–1
(b) 2.24 × 103
(b) 17.3
(c) 3.5 × 10–3
(d) 4.46 × 10–4
(c) 12.2
(d) 15.8
(e) 1.8 × 10–5
(e) 7.0
14. The Ka of acetic acid is 1.8 × 10–5. What is its pKa?
(a) 1.8 × 10–5
(b) 5.18
22. What is the H2O species concentration in any dilute
aqueous solution?
(a) zero
(b) infinite
(c) 4.74
(c) 55.5 M
(d) 4.74
15. What is the pH of a 0.100 M solution of acetic acid?
(a) 1.34 × 10–3
(d) 1.0 M
(e) 1.0 × 10–7 M
23. Which is the most likely pH of Windex glass cleaner?
(b) 2.87
(a) 2
(c) 1.00
(b) 4
(d) 4.74
(c) 7
(e) 3.74
16. What is the acetate ion (Ac – or CH 3 COO – )
concentration of the solution in Problem 15?
(a) exactly zero
(b) 3.74 M
(c) 0.100 M
(d) 1.34 × 10–3
(e) 1.8 × 10–6
17. What is the percent ionization of the acetic acid in
Problem 15?
(a) 1.34 %
(b) 0.134%
(c) 0.0014%
(d) 1.8 × 10–5%
(e) 1.8 × 10–3%
18. What is the pH of 6.0 N aqueous solution of NH3
(ammonia). It’s Kb = 1.8 × 10–5 .
(a) 0.0104
(c) 0.778
(b) 1.98
(d) 12.0
(e) 13.2
(d) 12
(e)14
A N S W E R S
1.
d
2.
c
3.
c
4.
b
5.
b
6.
a
7.
e
8.
c
9.
d
10.
b
11.
e
12.
a
13.
c
14.
c
15.
b
16.
d
17.
a
18.
d
19.
b
20.
a
21.
d
22.
c
23.
d
Code :- 05
CHEMISTRY
By:- Shailendra Kumar
H.O. :- Opp. Khuda Baksh Library, Ashok RajPath, Patna -4
B.O.:- House No. 5A/65, Opp. Mahual Kothi, Alpana Market, Patna
Confidence Building Test 05
1. What is the total concentration of Cl– in a mixture
that is 0.20 M MgCl2, 0.30 M NaCl and 0.40 M AlCl3.
(a) 0.30 M
(b) 0.90 M
(c) 2.80 M
(d) 1.90 M
2. How many moles of Ca(OH)2 are present in 350 ml
of 0.010 M aqueous solution of Ca(OH)2
(a) 35
(b) 3.5
(c) 0.0035
(d) 0.035
3. In problem (2) what is the molar concentration of
Hydroxide ion
(a) Zero
(b) 0.010 M
(c) 0.021 M
(d) 0.0070 M
4. What volume of 0.040 M aqueous HCl solution would
be required to entirely neutralize the solution in 350
ml of 0.010 M aqueous solution of Ca(OH)2.
(a) 175 ml
(b) 75 ml
(b) 350 ml
(d) 700 ml
5. Suppose 100 ml of 0.020 M aqueous H3PO4 are added
to the solution of 350 ml of 0.010 M aqueous solution
of Ca(OH)2. Assume the volumes are additive, what
are the concentrations of OH– species present after
reaction.
(a) 1/450 M
(b) 1/350 M
(c) 13/450 M
(d) 6/450 M
6. Identify the incorrect statement
(a) One equivalent of substance has one mol of
reactive capability
(b) The equivalent weight of a substance is the gram
of that substance in one equivalent
7.
of it exactly neutralizes 100 ml of 2.0 N sodium
hydroxide solution.
(a) 0.10 N
(b) 0.20 N
(c) 10.0 N
(d) 20.0 N
9. What is the H3O concentration in 1.0 M NaOH ?
(a) 1.0 M
(b) 1.0 × 10–14 M
+
(c) 1.0 × 1014 M
(d) 1.0 × 10–7 M
10. What is the OH– concentration in a neutral solution.
(a) exactly zero
(b) 1.0 × 10–14 M
(c) 7.0 M
(d) 1.0 × 10–7 M
11. The Ka acetic acid is 1.8 × 10–5, what is its Pka?
(log 1.8 = 0.26)
(a) 1.8 × 10–5
(b) 5.18
(c) 4.74
(d) 9.26
12. What is the pH of 0.10 M solution of acetic acid
(Ka of acetic acid = 1.8 × 10–5 )
(a) 1.34 × 10–3
(b) 2.87
(c) 4.74
(d) 3.74
13. What is the percent ionization of the 0.18 M acetic
acid (Ka = 1.8 × 10–5 )
(a) 4%
(b) 1%
(c) 0.01%
(d) 0.001%
14. What is POH of 10–2 M CH3 –COO–
Pka of acetic acid = 5
(a) 5.5
(b) 8.5
(c) 7.0
(d) 2
15. What is the percent hydration of 0.1 M acetate ion
Pka of acetic acid = 5
(c) One mol of HCl is also one equivalent of HCl
(a) 10–3 %
(b) 10–2 %
(d) The normality of a solution is the number of
equivalents per mole of that solution
(c) 10–4 %
(d) 10–5 %
Identify the incorrect statement
(a) 24.5 gm of H2SO4 is 0.5 of an equivalent of H2SO4
(b) 0.10 N solution of Ca(OH)2 is 0.050 M
(c) The equivalent weight of Ca(OH)2 is 74 gm/
equivalent
(d) A 6.0 M solution of H3PO4 is 18.0 N
8. What is the normality of an H2SO4 solution if 10.0 ml
16. What volume of 0.15 M HCl can be made from
7.5 ml of concentrated HCl (12 M)
(a) 0.060 L
(c) 0.60 L
(b) 6.0 L
(d) 6.0 × 102 L
17. How many moles of Mg(OH)2 can be precipitated
when 100 ml of 0.5 M MgCl2 solution is mixed with
100 ml of 0.25 M KOH.
(a) 0.025 mol
(b) 0.05 mol
(c) 0.0125 mol
(d) 0.5 mol
18. The first step in the ostwald process for producing
nitric acid, HNO3 from ammonia is represented by
this equation
4NH3 (g) + 5O2 (g) → 4NO (g) + 6H2O (g)
What volume of oxygen is needed to produce each
liter of NO?
(a) 0.80 L
(b) 5.0 L
(c) 1.25 L
(d) 22.4 L
19. What volume of 0.500 M CaCl2 solution is needed to
prepare 250 ml of solution that has a chloride
concentration of 0.100 M
(a) 12.5 ml
(b) 50 ml
(c) 25 ml
(d) 100 ml
20. The limiting reagent in a particular reaction can be
recognized because it is the reagent
(a) with the smallest coefficient in the balanced
equation
(b) that has the lowest mass in the reaction mixture
(c) that is present in the smallest molar quantity
(d) that would be used up first
21. How many gram of carbon are present in 0.50 mol
of sucrose (C12H22O11)
(a) 60 gm
(b) 72 gm
(c) 90 gm
(d) 120 gm
22. The major commercial source for bromine is deep
brine well where the concentration of bromide ion
can be high as 5000 ports per million by mass. What
is this concentration when expressed as a mass
percentage?
(a) 0.005%
(c) 0.05%
(b) 0.5 %
(d) 5%
23. The pH of a 0.005 M aqueous solution of sulphuric
acid is approximately:
(a)0.005
(b) 2
(c) 1
(d) 0.01
24. The pH of a 10–10 NaOH solution is approximately:
(a) 10
(c) 1
(b) 7
(d)14
25. If the dissociation constant of an acid HA is 1 × 10–5,
the pH of a 0.1 M solution of the acid HA will be
approximately:
(a) 3
(b) 5
(c) 1
(d) 6
26. The pH of a solution is 5.0. To this solution sufficient
acid is added to decrease the pH to 2.0. The increase
in hydrogen ion concentration is :
(a) 1000 times
(b) 5/2
(c) 100 times
(d) 5 times
27. When the pH of a solution is 2 the hydrogen ion
concentration is :
(a) 1 × 10–14 M
(c) 1 × 10–7 M
(b) 1 × 10–2 M
(d) 1 × 10–12 M
28. The pH of 1/1000 N KOH solution is :
(a) 10–11
(b) 3
(c) 2
(d) 11
29. Assuming complete dissociation the pH of a 0.01 M
NaOH solution is equal to :
(a) 2.0
(b) 14.0
(c) 12.0
(d) 0.01
30. The pH of the solution obtained by mixing 10 mL of
10–1 N HCl and 10 mL of 10–1 N NaOH is:
(a) 8
(b) 2
(c) 7
(d) None
31. Which addition would not change the pH of 10 mL of
dilute hydrochloric acid :
(a) 20 mL of the same dilute hydrochloric acid
(b) 5 mL of pure water
(c) 10 mL of pure water
(d) 10 mL of concentrated hydrochloric acid
32. 10 mL of a solution contains 0.1 M NH4Cl + 0.01 M
NH4OH. Which addition would not change the pH of
the solution:
(a) Adding 1 mL water
(b) Adding 5 mL of 0.1 M NH4Cl
(c) Adding 5 mL of 0.1 M NH4OH
(d) Adding 10 mL of 0.1 M NH4Cl
33. At 90°C, pure water has [H3O+] = 10–6 mol/litre.
The value of Kw at 90°C is:
(a) 10–6
(b) 10–12
(c) 10
(d) 10–8
–14
34. The pH of 10–2 N HCl would be approximately:
(a) 1
(b) 1.5
(c) 2
(d) 2.5
35. 0.4 g NaOH present in one litre solution shows the
pH :
(a) 12
(b) 2
(c) 6
(d) 10
36. pH of a 10 M solution of HCl in water is
–8
(a) 8
(b) –8
(c) Between 7 and 8
(d) Between 6 and 7
A N S W E R S
1.
d
32.
a
2.
c
33.
b
3.
c
34.
c
4.
a
35.
a
5.
a
36.
d
6.
d
7.
c
8.
d
9.
b
10.
d
11.
c
12.
b
13.
b
14.
a
15.
b
16.
c
17.
c
18.
c
19.
c
20.
d
21.
b
22.
b
23.
b
24.
b
25.
a
26.
a
27.
b
28.
d
29.
c
30.
c
31.
a