Download answer ch6 - Mr Khaled Nasr

Advanced Chapter 6
Chapter 6 : Section (A)
Q1 Choose the correct answer:
1. The number of particles in one mole is the -----------------------------a- Avogadro constant
b- gram.
c- atomic mass unit
d- kilogram.
2. Avogadro’s number equals --------------a- 60.2 10 . b- 6.02 10 . c- 0.602 1023 c . 6.02 1023
How many atoms are represented in the formula Ca3(PO4)2.
a-3
b-8
c-12
d-13
4. How many molecules are there in one mole of CH4?
a-5
b-1
c-6.02x1023
d-5x6.02x1023
5. How many hydrogen molecules are there in one mole of hydrogen gas (H2)?
a- 1
b- 2
c- 6.02 1023
d- 2×6.02 x 1023
6. How many hydrogen atoms are there in one mole of hydrogen molecules (H2)?
a- 2(6.02 1023 )
b- 6.02 1023
c- 2.02
d- 1.01
7. How many atoms are there in 1 mole of water (H2O)
a- 3
b- 6.02 1023
c- 2 (6.02 x 1023)
d- 3(6.02 1023 )
23
The number of moles in 1.806 x 10 atoms of copper is ---------------a-1
b-0.1
c-0.3
d. 10
How many moles of magnesium atoms are there in 7.32 1023 atoms?
a- 1.22 x 1 0 moles
b- 6.02 x 1 0 moles.
C- 8.23 x 1026 moles
d- 4.44×101 moles
23
3.
4.
5.
6.
7.
8.
9.
32
C3 H7OH    O2 
  CO2     H 2O
10. One mole of C3H7OH underwent combustion as shown in the reaction above. How many moles
of oxygen were required for the reaction?
a- 2 moles.
b- 3 moles.
c- 7/2 moles. d- 9/2 moles.
11. . How many moles of potassium chlorate (KClO3) may be produced from 2.4 moles of chlorine
assuming that a sufficient amount of potassium hydroxide is available?
3Cl 2  6KOH 
 5KCl  3H 2O  KClO3
a- 1.20
b- 0.80
c- 7.2
12. According to the reaction opposite:
d- 0.40
H 2  I 2 
 2HI
The number of molecules of hydrogen iodide produced from the reaction of 0.3 mole of
hydrogen molecules with a sufficient amount of iodine is ---------------a- 3.612 x 1023
b- 7.826 x 1023
c- 24.08 x 1023 d- 12.04 1023
13. From the previous reaction, the number of moles of hydrogen iodide produced from the
reaction of 1.25 mole of iodine with a sufficient amount of hydrogen is -----------------a- 2.5 moles. b- 3 moles. c- 1.25 moles.
d- 0.63 mole.
14. How many moles of sodium metal are required to produce 1.505 x 1023 molecules of hydrogen
gas in the following reaction? 2 Na  HCl 
 2 NaCl  H 2
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a- 1 mole
b- 2 moles.
d- 0.4 mole.
c- 0.5mole.

15. In the reaction 2FeSO4 
 Fe2O3  SO2  SO3
16.
17.
18.
19.
20.
21.
22.
23.
The number of sulphur trioxide molecules which are produced from thermal decomposition of
2.6
moles of iron (II) sulphate is-----------------------a- 6.02 x 1023
b- 7.826 x 1023
c- 24.08 x 1023
d- 12.04 x 1023
What is the mass of one mole (molar mass) of CaCO3
(Ca = 40, C = 12,O =16)
a-68g
b-75g
c-82g
d. 100g
What is the molar mass of Ca(NO3)2
(Ca = 40, N = 14, O =16)
a-164g
b-150g
c-82g
d. 70g
The mass of 1 mole of nitrogen gas (N2) equals -------------------------a-82g
b-42g
c-28g
d. 14g
The mass, in grams, of 0.0790 moles of aluminum equals ------------------- (Al =27)
a-21.3g
b-2
c-21g
d. 0.213g
How many moles of calcium are there in 0.544g of calcium?
Ca = 40
a- 0.0136
b- 0.0773
c- 0.554
d. 3.11
How many moles of sucrose, C12H22O11 are there in 1222g of sucrose?
(C = 12, H = 1, O = 16)
a- 0.258
b-1.22
c-3.57 d. 10.8
The mass of one mole of phosphorus in the vapour state is 124 grams so, its formula in the
vapour state is ---------------a-P
b-P2
c-P4
d. P6
How many moles of CaO can be produced from the thermal decomposition of 1 72g of CaCO3

CaCO3 
 CaO  CO2
a- 2.2 moles.
(Ca=40,C=12,O=16)
b- 0.58 moles.
c- 1.72 moles.
D. 4 moles
24. How many moles of electrons are required to reduce 2.93g of nickel ions from melted NiCI2?
Ni 2  2e 
 Ni
(Ni= 59)
a-0.05
b-0.1
c-1.0
d- 1.5
25. Tungsten metal, used to make glowing bulb filaments, is produced by the following reaction:
WO3  3H 2 
W  3H 2O
(W=184, O=16)
How many grams of tungsten can be obtained from 0.0207 moles of WO3?
a- 2.40
b- 4.21
c- 3.81
d- 4.32
26. From the previous reaction, how many grams of tungsten can be obtained from 20.36 grams of
WO3?
a-25.6
b- 16.15
c- 97.82
d-6.12
27. How many grams of carbon are present in 270 grams of glucose, C6H12O6?
a- 120 grams.
b- 18 grams.
c- 108 grams.
(C=12, H=1,O=16)
d- 180 grams.
8CO2  10H 2O
28. 80.0 grams of butane burns according to the chemical equation: 2C4 H10  13O2 
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What mass of oxygen reacts?
a- 603.2 g
(C = 12, H = 1, O = 16)
b- 286.9 g
c- 22.3 g
d- 416 g
29. How many grams of hydrogen gas can be produced from the following reaction if 65g of HCI are
reacted completely with a sufficient amount of zinc?
 ZnCI2 (aq) + H2 (g)
Zn (s) + 2HCI (aq) 
a- 2.25g
b- 1 .78g
(H = 1, C = 35.5)
c- 3.6 g
d- 7g
30. Every 4 grams of hydrogen gas (H2 )contain---------------------------a- 6.02 x 1023 molecules
b- 0.602 x 1023 molecules.
c- 6.02 x 1022 molecules
d- 12.04 x 1023 molecules.
31. The mass of one sodium atom equals -----------------a-2.6x 10-24
b-3.82x 10-23
c-1.66 x 10-24
d- 1.38 x 10-23
32. The mass of 2.7 x 1023 atoms of silver equals -----------------a- 84.5g
b- 48.4g.
c- 96.8g.
d- 24.2g
33. There are------------------- iron atoms in a typical two-inch nail which has a mass of 5.6 grams.
a- 0.602 x 1023
b- 6.02 x 1023
c- 60.2 x 1023
d- 602 x 1023
34. The mass of 7.6 x 1023 molecules of sodium carbonate (Na2CO3) equals ---------(Na = 23, C = 12,O= 16)
a- 106g
b- 83g
c- 133.8g
d- 391g
35. About how many molecules of water do you drink in a glassful? (A small glass holds about 180 cm3,
(1cm3 of water has a mass of about 1 gram.)
(H = 1, O= 16)
a- 0.602x 1023
b- 6.02x 1023
c- 60.2x 1023
d- 602 x 1023
36. The mass of 1.204 x 1024 atoms of hydrogen equals --------------- (H = 1)
a-1g.
b-2g.
c-3g
37. How many atoms are there in 34.6 g of carbon dioxide?
a- 14.20x 1023
38.

2K + Br2 
b- 12.1x 1023
c- 4.73x 1023
d-4g.
(C = 12, O = 16)
d- 0.786
2KBr
From the reaction above, the number of potassium bromide molecules produced from 20 grams
potassium equals -------------------------- (K = 39)
a- 3.09 x 1023
b- 6.17 x 1023
c- 18.52 x 1023
d- 93 x 1023
39. The number of oxygen atoms produced from the thermal decomposition of 13.5 grams of sodium
nitrate equals---------------- (Na = 23, N = 14, O = 16)
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
2 NaNO3 
 2 NaNO2  O2
a- 9.56 x 1022
b- 3.8 x 1022
c- 2.86 x 1023
d- 1.9 x 1023
40. Standard conditions (STP) are:
a- 0°C and 2 atm.
b- 273 K and 760 mm Hg.
c- 0°C and 7.6cm 1
d- 0 K and 760 mm Hg.
41. The volumes of gases involved in a reaction and the gases produced are ----------------a- existing in fixed ratios.
b- existing in equal volumes.
c- inversely proportional.
d- not related to one another.
42. Which of the following states that: Equal volumes of gases at the same temperature and pressure
contain the same number of particles?
a- Boyle’s law
b - Gay-Lussac’s law.
c- Charles’s law
d- Avogadro’s principle.
43. At STP, one molar volume is ---------a- 22.4 L.
b- 32L.
c- 10L.
d- 6.02 x 1023L
44. How can the molar volume of a gas be defined?
a- The volume that one mole occupies at STP
b- The volume that one gram occupies at STP.
c-The volume that one mole occupies at 100°C and 1 atm pressure.
d- The volume that one gram occupies at 100°C and 1 atm pressure.
45. What is the volume of 2.0 moles of a gas at STP?
a- 44.8L
b- 22.4L.
c – 0.223L
d- 0.446L
46. The number of moles in 33.6 L of oxygen gas O2 at STP equals -----------------a- 48 moles.
b- 3 moles
c- 1.5 moles.
d- 32 moles.
47. How many liters of O2 can be produced from 2 moles of KCIO3 by decomposition

2KClO3 
 2KCl  3O2
a- 11.2L
b- 22.4
c- 44.8
d- 67.2
48. The number of moles of nitrogen gas required to produce 2 L of ammonia gas at STP equals ---------electric spark
N2  3H 2 
 2 NH3
a- 8.9 x 10-2
b- 4.5 x 10-2
c- 0.36
d- 0.178
49. If 10 L of CO gas react with a sufficient amount of oxygen completely, then how
many liters of CO2 gas are formed?
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2CO  O2 
 2CO2
Page 4
a- 5
b- 10
c- 15
d- 20
50. What volume, in liters, will be occupied at STP by 4g of H2? (H=1)
a-11.2
b-22.4
c- 33.6
d- 44.8

 2ZnO(S) + 2 SO2(g)
51. 2 ZnS (s) + 3O2 (g)
( Zn = 65.5 O =16)
If the reaction above took place at standard temperature and pressure, then what was the volume of
O2(g) required to produce 40.0 grams of ZnO(S)?
(40)(2)
L
(81.4)(3)(22.4)
(40.0)(2)(22.4)
c
L
(81.4)(3)
(40.0)(3)
L
(81.4)(2)(22.4)
(40.0)(3)(22.4)
d(81.4)(2)
a
b-
52. What is the mass, in grams, of 1 L of nitrous oxide, N2O at STP? (N = 14, O=16)
a-1
b-1.96
c-11.2
d-22
53. If five liters of gas at STP have a mass of 1 2.5g, then what is the molar mass of the gas!
a- 12.5g.
b- 25.0g.
c- 17.5g.
d- 56.0g.
54. The mass of iron metal produced from the reaction of iron ore with 3.5L of carbon monoxide at STP
as in the following reaction equals
3CO+Fe ----------> 2Fe+3CO2 (Fe=56)
a- 5.8 g
b- 8.75 g
c- 2.9 g
d- 17.5g
55. One liter of oxygen gas at STP contains ---------------- oxygen molecules.
a- 6.02 x 1023
b- 12.04 x 1046
c- 0.269 x 1023
c - 0.54 x 1023
56. How many hydrogen atoms are present in 12L of hydrogen gas at STP?
a- 6.5 x 1023
b- 0.54
c- 2.06 x 1023
d- 13.48 xl024
57. A gas at STP which contains 6.02 x 1023 atoms and forms diatomic molecules will occupy -----a- 11.2L
b- 22.4L.
C- 33.6L.
d- 67.2L.
500C
 Fe3O4  4H 2
58. 3Fe  4H 2O 
I- How many iron atoms are required to produce 11.5 L of H2 gas?
a- 2.32 x 1023
b- 7.7 x 1022
c- 9.27 x 1023
d- 14.3 xl023
II - What is the volume of H2 gas produced from 9.03 x 1023 atoms of iron?
a- 22.4L.
b- 89.6L.
c- 44.8L.
d- 11 .2L.
59. If the molecular mass of NH3 is 17, then what is the density of this compound at STP?
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a- 0.25 g/L
b- 0.76 g/L
c- 1.52 g/L
d- 3.04 g/L
60. If the density of a diatomic gas is 1.43 g/L, then what is its molar mass?
a- 16g
b-32g
c-48g
d-64g
61. Which one of the following gases will have the greatest density at STP?
a- H2
b- O3
c- Cl2
d- CO2
(H = 1,O = 16, C = 12, CI = 35.5)
62. The concentration of 2moles of Na2CO3 dissolved in one liter of equals ---------------a-2M
b-O.5M
c-1M
d-3M
63. The number of moles of sodium hydroxide in 25mL of its solution whose concentration is 0.2 mole/L
is ----------a- 5 x 10-3
b- 5 x 10-2
c- 2 x 10-3
d- 2 x 10-2
64. Two moles of.0.8M sulphuric acid occupy -------------------a- 2.5mL
b- 2.5L
c- 0.4mL
d- O.4L
65. How many grams of NaCI are dissolved in 500mL of a 0.05 M solution of NaCI? (Na=23,Cl=35.5)
a- 0.05 g.
b- 0.29g.
c- 1.46g.
d- 2.29g.
66. What volume, in mL, of a 0.181 M solution is required to provide 0.07169 of KMnO4?(K = 39, Mn =
55, O =1 6).
a- 4.52
b- 2.50
c- 3.22
d- 3.62
67. What is the molar concentration of barium hydroxide, Ba(OH)2 in a solution formed by the reaction
of 0.34g of barium with enough water to give 200.0mL of solution? (Ba = 137,O= 16, H = 1)
Ba( s ) 2H 2O(l ) 
 Ba(OH )2( aq )  H 2( g )
a-1.2x 10-2
b- 1.9x10-2
c-9.2x10-1
d-6.2x10-1
68. The number of molecules in 255 mL of 1 .25M H2SO4 equals ----------a- 0.318
b- 1.92x 1023
c- 1.92x 1026
d- 318.75
69. How many moles of ions are produced when two moles of sodium carbonate(Na2CO3) dissolve in
water?
a- 3
b- 4
c- 6
d- 10
70. How many ions are produced when one mole of sodium phosphate (Na3PO4) dissolves in water?
a- 2(6.02 x 1023)
b- 3(6.02 x 1023)
c- 4(602 x 1023)
d- 8(602 x 1023)
71. How many ions are produced when one mole of sodium chloride dissolves in water?
a- 2
b- 6.02 x 1023
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c- 1.8 x 1024
d- 1.2 x 1024
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72. The number of moles of ions produced on dissolving 40g of sodium sulphate is -----(Na=23, S=32,O=16)
a- 0.3
b- 0.85
C- 0.6
d- 1
73. How many grams of sodium sulphate are dissolved in water to produce 1 .505x1022sulphate ions?
a- 35.5
b- 3.55
c- 7.1
d- 71
74. How many ions of sodium are produced when 4.25 g of sodium nitrate are dissolved in water?
(Na = 23, N = 14, O = 16)
a- 3.01x1023
c-3.01x 1022
b- 3.01 x 1024
d- 301 x 1023
75. How many H+ ions does a 5M solution of HCI have in 1 L in water?
a- 5
b- 6.02 x 1023
c- 1 .204 x 1023
d-3.01 x1024
76. The weight percentage of Na2CO3 in its solution is 15% thus, there is --------- of sodium carbonate
dissolved in 100 g of the solution.
a-30g
b-15g
c-l0g
d- 100g
77. What is the mass percent of boron in boric acid H3BO3 (B= 11, O = 16, H = 1)
a- 17.74%
b- 22.10%
c- 38.00%
d- 45.30%
78. Iron ore is converted into pure iron by the following reaction, which occurs at extremely high
temperatures.
 700 C
Fe2O3  3CO 
2Fe  3CO2
A 1600 gram sample of iron ore reacted completely to form 560 grams of pure iron. What was the
percent of Fe2O3 by mass in the original sample? (Fe = 56, C = 12,O = 16)
a- 25%
b- 33%
c- 50%
d- 67%
79. A sample of sodium hydroxide was exposed to atmospheric air for a short time where it has
absorbed carbon dioxide gas. When analyzed, it is found that it contains 10 p.p.m. of Na2CO3 i.e the
amount of Na2CO3 in every kilogram sodium hydroxide is -------------a- 10 milligrams
b- 10 grams.
c- 100 milligrams.
d- 100 grams.
80. Molarity equals ------------------------a- moles of solute per liter of solution.
b- grams of solute per gram of solution
c- grams of solute per titer of solution.
d- liters of solute per kilogram of solution.
81. A solution of known molarity used in an acid-base titration is known as a/an ------------a- aliquot‫ قاسمة‬.
b- heterogeneous solution.
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c- indicator.
d- standard solution.
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28.Titration is the general process of determining the------------- of an acidic or solution through the use
of an acid-base reaction.
a- boiling point
b- density
c - molarity
d- polarity
83. An acid-base reaction is called -------------- a reaction
a- combination
b- neutralization
84. Phenolphthalein is --------------a- red , colourless
c- single- replacement
d- synthesis
in acidic medium and ------------ in basic medium
b- colourless , red
c- red , yellow d- yellow, red
85. A 22.5 mL of 0.122M HCI neutralizes 30.0 mL of a KOH solution. What is the molarity of the KOH
solution?
a-0.0915M.
b-0.163M.
c- 0.00445M
d- 1.08M
86. What volume of 0.0500M HNO3 is required to neutralize 52.6 ml of 0.250M LiOH?
a- 10.5mL
b- 52.6mL
c- 263ml
d- 525ml
87. A diprotic acid (Acid that contains two hydrogen protons (2H+)) in its molecule e.g. H2SO4 was
titrated with a solution of sodium hydroxide. For 25mL of the acid, 87.42mL of a 1.95M solution of NaOH
was required to reach the equivalent point. Which of the following expressions is equal to the initial
concentration of the diprotic acid?
(25)
(87.42)(1.95)
(87.42)(1.95)
c
(25)(2)
a
(87.42)(1.95)
(25)
(25)(2)
d(87.42)(1.95)
b-
88. If you titrate a 1M H2SO4 solution against 50mL of 1 M NaOH solution, what volume of H2SO4
will be needed for neutralization?
a- 10L.
b- 0.025L.
c- 25L.
d- 0.05L.
89. What is the molar concentration of H2SO4 in a solution if 31.91 mL of it is required to titrate
2.474g of Na2CO3
(C = 12, O = 16, H = 1, Na = 23)
H 2 SO4  Na2CO3 
 Na2 SO4  H 2O  CO2
a-0.73
b- 1.122
c- 0.3657
d- 0.5222
90. The mass of washing soda crystals before heating is 5 grams and after strong heating at a
constant mass is 1.853 grams. What is the % of water of crystallization of washing soda?
a- 0.6294%
b- 62.9%
c- 37%
d- 0.37%
91. The molecular formula for hydrated ferric oxide, or rust, is generally written a Fe2O3.XH2O
because the water content in rust can vary. If a 1 molar sample of hydrated ferric oxide is found
to contain 108g of H2O, then what is the molecular formula for the sample?
a  Fe2O3 .H 2O
b- Fe2O3 .3H 2O
c- Fe 2O3.6 H 2O
d- Fe2O3 .10H 2O
92. Two grams of silver chloride were precipitated when hydrochloric acid was added to a solution
of silver nitrate. What was the mass of silver nitrate?
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AgNO3  HCl 
 AgCl  HNO3
(Ag 108, 14, 0= 16, Cl= 35.5
a-3g b-5g
c- 2.4g
d- 7g
93. When excess hydroxide ions were added to 1.0 liter of CaCI2 solution, Ca(OH)2 precipitate was
formed. If all of the calcium ions in the solution were precipitate in 7.4 grams of Ca(OH)2 then
what was the initial concentration of the CaCl2 solution? (Ca = 40, H = 1, O = 16, Cl = 35.5)
a- 0.05 molar b- 010 molar
c- 0.15 molar
d- 0.20 molar
Q2:Write scientific terms:
(1)
(2)
(3)
(4)
(5)
The number of atoms, molecules or ions in one mole of any substance.
A unit of quantity that consists of 6.02 x 1023 particles.
The mass in grams of one mole of any pure substance.
The volumes of gases involved in a reaction and the gases produced exist in fixed ratios.
The law which states that equal volumes of gases under identical conditions of pressure and
temperature contain equal numbers of particles.
(6) A mass per unit volume of a substance.
(7) A type of chemical analysis that aims at identifying the constituents of a mixture or compound.
(8) A type of chemical analysis that aims at determining the concentration or quantity of the
constituents of a sample.
(9) The weight of a substance in 100 grams of its solution.
(10)The number of moles of solute per liter of solution.
(11)A solution containing 1 mole of solute in 1000mL of solution.
(12)A method of quantitative analysis that is based on measurement of the volume of the substance
to be analyzed.
(13)A solution of accurately known concentration.
(14)A chemical process in which the concentration of a solution can be determined by using
standard solution of known concentration.
(15)A reaction which is used for the determination of the concentration of acids and bases.
(16)A reaction which is used for the determination of the concentration of redox substance.
(17)A reaction which is used for the determination of the substances that form sparingly soluble
products.
(18)The point at which complete reaction takes place in titration process.
(19)A compound that exhibits different colours depending on the nature of the medium.
(20)A method of quantitative analysis that depends on the separation of the analyte by volatilization
or precipitation, then determining its amount by weight.
(21)A method of gravimetric analysis that is based on the volatilization of element or compound to
be determined.
(22)A type of filter papers upon ignition leaves no ash.
(23)A method of gravimetric analysis that is based on precipitation of the analyte in the form of pure
sparingly soluble compound with constant and known chemical structure.
Q3 Correct the underlined words:
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Page 9
1.
2.
3.
4.
5.
6.
One mole of sodium atoms contains 23 atoms of sodium.
Half mole of chlorine molecules contains 17 molecules of chlorine.
One mole of potassium sulphate (K2SO4) contains 54 atoms.
One mole of nitrate ions contains 2 nitrate ions.
Three moles of hydrogen ions contain 6.02x1023 ions of hydrogen.
2 moles of ammonia gas contain 2.41 xl 024 ammonia molecules.
197
7. Half mole of gold ( Au79
) atoms weighs118 grams.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
0.05mole of ethylene (C2H4) molecules weighs 22 grams. (C = 12, H=1)
6.02 x 1023 molecules of aluminum chloride weigh ONE gram.(Al =27, Cl =35)
One mole of acetylene gas occupies a volume of ONE liters at STP.
11 0.1mole of hydrogen gas occupies 30 liters at STP.
3.23X1023 molecules of nitrogen gas occupy 5 liters at STP.
15 grams of chlorine gas occupies 2 liters at STP (Cl = 35.5 )
The molar mass of a gas at STP whose density is 1.96 grams/liter is 20 grams.
Density of a gas at STP depends on the molar volume only.
The density of O2 gas is EQUAL TO that of O3 gas at STP. (O = 16)
The concentration of 1.3 moles of sodium carbonate dissolved in 200mL of the solution is 3M.
30 grams of potassium hydroxide is dissolved in 122 mL of water to make 6M solution (H= 1,O=
16, K = 39)
One mole of potassium bromide (KBr) dissociate in water producing 3 ions.
The number of ions produced by dissolving 8.2 grams of sodium sulphate in water is 18.06 ions.
(S = 32,O = 16, Na = 23)
Quantitative analysis is used to identify the constituents of an unknown substance.
A solution which contains 2 moles of solute in enough water to make a 1 liter of solution called
molar solution.
A mixture contains 6ppm iron (Ill) oxide means that every 100 grams of the mixture contain 6
milligrams of iron (Ill) oxide.
Standard solution is a solution of accurately known volume
Titration process is a method of gravimetric analysis.
Methyl orange has yellow colour in acidic medium and blue colour in basic medium.
Phenolphthalein has green colour in basic medium and blue colour in acidic medium.
Litmus solution is colourless in acidic medium and yellow in basic medium.
Phenolphthalein has blue colour in basic medium and yellow colour in acidic medium.
Volatilization and precipitation methods are methods of qualitative volumetric analysis.
Q4 Give reason for each of the following:
(1) The mole consists of a huge number of particles.
(2) The number of molecule in one mole of acetic acid equals the number of molecules in
one mole of nitric acid.
(3) One liter of any gas contains the same number of molecules at STP.
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(4) Twenty eight grams of nitrogen gas occupy the same volume of two grams of hydrogen
gas at (STP).
(5) The density of any gas at STP depends only on its molar mass.
(6) Hydrogen gas has the least density among gases at STP.
(7) Indicators are used in the acid - base titrations.
(8) Hydrochloric acid solution can not be used to differentiate between methyl orange
indicator and litmus indicator.
(9) Sodium hydroxide solution can not be used to differentiate between bromothymol blue
indicator and litmus indicator.
(10)Standard solution is used in titration process.
(11)Ashless filter papers are used in the chemical analysis by precipitation method.
Q5 What is meant by each of the following:
1. Avogadro’s number.
12. Weight percent.
2. Mole.
13. Molar concentration (mole/liter).
3. Molar mass.
14. ppm.
4. Molar volume.
15. Volumetric analysis.
5. STP.
16. Standard solution.
6 Gay - Lussac’s law
17 Titration process
7. Avogadro’s law.
18. Neutralization reactions.
8. The gas density.
19. Indicator.
9. Analytical chemistry.
20. Gravimetric analysis.
10. Qualitative analysis.
21. Volatilization method.
11. Quantitative analysis.
22. Precipitation method.
Q6: What is the scientific principle of each of the following:
1. Volumetric analysis.
2. Gravimetric analysis.
3. Volatilization method.
4. Precipitation method.
Q7: What is the scientific contribution of each of the following:
1. Gay- Lussac. 2. Avogadro.
Q8:Mention the mathematical formulae relating between each two of following quantities:
(1) The number of moles of a gas and its volume at (STP).
(2) The molecular mass of the gas and its density (g at STP).
(3) The concentration of the solution (mole/L) and both the number of moles and the solution
volume (L).
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(4) The number of produced ions in the solution of a totally ionizable substance the number of its
dissolved moles.
(5) The volumes and concentrations of each of the acid and the alkali at the point of their titration.
Q9:Chemical analysis provides important information for human life. Mention importance of chemical
analysis in different fields.
Q10: Is the following statement true or false? (Explain your answer.) ‘Equal volumes of different gases at
STP do not have equal masses.
Q11: What do we mean by saying that:
1. A 10% aqueous solution of calcium chloride.
2. A 5% aqueous solution of glucose.
3. A mixture contains 6.5 ppm of gold.
4. Molar solution of sulphuric acid.
5. A 0.5 molar solution of sodium hydroxide
Q12: Explain why sodium hydroxide solution not hydrochloric acid solution can be used to differentiate
between methyl orange indicator and litmus indicator whereas hydrochloric acid solution not sodium
hydroxide solution can be used to differentiate between bromothymol blue indicator and litmus
indicator.
Q13:
Problems
1. How many particles (atoms, molecules or ions) are present in each of the following:
a- 1 mole of copper (Cu) atoms. b- 0.5 mole of phosphate (P0 ions. c- 2 moles of CO
molecules.
2. Determine the number of moles in each of the following:
a- 1.80 x 1024 atoms of lead.
b- 1.20 x 1025 ions of sulphate.
c- 3.9 x 1023 molecules of CH4
3. How many moles of oxygen atoms are present in 5.00 moles phosphorus pentoxide (P2O5)

4. From the following equation: CaCO3 
 CaO  CO2
a. How many molecules of calcium oxide are produced from heating 0.1 mole of
calcium carbonate?
b. How many moles of calcium carbonate are required to produce 0.7 mole of
carbon dioxide?
5. Carbon disulphide is an important industrial solvent. It is prepared by the reaction of coke with
sulphur dioxide. 5C(S) + 2SO2 (g) ----------- CS2 + 4CO
a- How many moles of carbon are needed to react with 5.44 moles SO2?
b- How many moles of carbon monoxide are formed at the same time when 0.246 mole
CS2 forms.
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
 2CO  2H 2O
6. The equation for the complete combustion of ethene (C2H4) is: C2 H 4  3O2 
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
If 2.70 moles C2H4 are reacted with sufficient amount of oxygen, then calculate number of moles
of water produced.
What is the weight of one mole of Ca(OH)2 (Ca = 40, H = 1, O =16)
A student examined 2.0 moles of an unknown carbon compound and found that the compound
contained 48 grams of carbon, 64 grams of oxygen, and 8grams of hydrogen, which of the
following could be the molecular formula of the compound?
(C = 12,O = 16, H = 1)
a- CH2O
b- CH2OH
c- CH3COOH
d- CH3CO
Determine the number of moles in each of the following:
a- 275 g boron.
b- 200 g sodium sulphate.
c- 120 tones of calcium,
(B=11 S=32 Na=23 O=16 Ca=40)
What is the weight of each of the following?
a- 0.100 mole sulphur.
b- 1.25 mole glucose
c- 6.02 x 1023 molecules I2?
d- 2.5 x 1020 atoms of magnesium.
(S = 32, C = 12, H = 1,O = 16, I = 127, Mg
How many molecules in each of the following:
a- 119 g KBr
b- 20 g NaCI.
(K = 39, Br = 80, Na = 23, Cl = 35.5)
Arrange the following in order of mass from the smallest mass to the largest:
1.0mole Ar, 3.0 x 1024 atoms Ne, 20g Kr. (Kr = 84, Ar = 40, Ne = 20)
Which of the following contains the largest mass of nitrogen atoms?
a- 0.40 mole N2O5
b- 0.60 mole NO.
c- 0.15mole N2O
d- 0.50mole NO2
i. (N = 14, 0 = 16).
1 Methanol is made by reacting carbon monoxide and hydrogen at high temperature and
pressure.
(C=12,O=16,H=1)
CO(g)+ 2H2 ----------- CH3OH
a- How many moles of carbon monoxide are needed to produce 3.60x102 g of CH3OH?
b- Calculate the number of grams of hydrogen needed to produce 4.00 moles of CH3OH?
c- How many grams of hydrogen are necessary to react with 2.85moles CO?
A pure sample of KCIO3 contains 71 grams of chlorine atoms. (K = 39, Cl = 35.5, O = 16)
a- What is the mass of the sample?
b- Determine the number of moles of chlorine atoms present in 36.5 g of KCIO3?
How many moles of KOH are needed to neutralize 196g of sulphuric acid? (s=32,O=16,H=1)
How many grams of sodium atoms are present in 23g of sodium carbonate? (C=12,Na=23,O=16)
Acetylene gas (C2H2) is produced by adding water to calcium carbide (CaC2)
a- CaC2 + 2H2O -------- C 2H2
+ Ca(OH)2 How many grams of acetylene are
produced by adding water to 5.OOg CaC2? (C = 12, Ca = 40, H= 1)
A sufficient amount of hydrogen is ignited with 4g of oxygen. How many grams of water can be
 2H 2O
formed? 2H 2  O2 
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(H=1,O=16)
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20. An impure sample of Hg(NO3)2 weighing 64.5g was dissolved in water. The dissolved Hg(NO3)2
 Mg ( NO3 )2  Hg
but not the impurities,:then reacted with excess Mg metal. Hg ( NO3 )2  Mg 
What was the mass percent of Hg(NO3)2 in the sample if 23.6 g of Hg were produced?
(Hg = 200.6, N = 14, 0 = 16)
21. What is the mass of one carbon atom? (C = 12)
22. What volume will the following gases occupy at STP:
a- 0.554 mole of oxygen.
b- 1 mole of hydrogen.
C- 2.5 moles of nitrogen.
23. Determine the number of moles of the following gases at STP:
a- 6.72 L of ammonia gas.
b- 26.88 L of methane gas.
24. Consider this equation: CS + 3O2 ----------- CO2 + 2SO2(g)
a- How many moles of carbon disulphide are needed to produce 16.6L of sulphur dioxide at STP?
b- Calculate the volume of sulphur dioxide produced at STP when 27.9mL O2 reacts with carbon
disluphide
c- How many milliliter of carbon dioxide are produced at STP when 0.38L s formed?
25. In the following reaction, how many liters of SO2 at STP will result from the comlete burning of

 SO2
pure sulphur in 8Loxygen? S  O2 
26. What volume, in liters, of NH3 is produced when 22.4L of N2 are made to combine completely
with a sufficient quantity of H2 under appropriate conditions?
27. Under STP conditions, what is the mass of the following gases:
a- 22.4L of PH3
b- 33.6L of chlorine gas (H=1
Cl=35.5
P=31)
28. What is the volume at STP occupied by:
a- 48 g of O3
b- 120 g of SO3
(O = 16,
S = 32)
29. Which occupies more volume at STP:
a- 24.5 grams of N or 24.5 grams of NH3
b- 10.0 grams of SO or 20.0 grams of NO2
(N =14, H = 1,O = 16, S = 32)
30. What mass of aluminum will be completely oxidized by 44.8L of oxygen at STP? (Al = 27)
4Al + 3O2 ------------
2AI2O3
31. How many liters of 02 at STP can be released from thermal dissociation of 50.3 grams of sodium
chlorate (NaClO3 into sodium chloride and oxygen?
(Na = 23, C = 35.5, 0 = 16)

2 NaClO3 
 2 NaCl  3O2
32. Lithium nitride reacts with water to form ammonia and aqueous lithium hydroxide.
aWhat mass of water is needed to react with 32.9g Li
bWhen the above reaction takes place, how many molecules of NH are produced?
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c-
Calculate the number of grams of Li that must be added to an excess of water to
produce 15.Of NH3 (at STP).
(N 14, Li = 7)
33. Ammonium nitrate will decompose explosively at high temperatures to form nitrogen, oxygen,

 2 N2  4H 2O  O2
and water vapor. 2 NH3 NO3 
What is the total number of liters of gas formed when 228g NH4NO3 is decomposed?
(assume STP)
(0 = 16, N = 14, H = 1)
34. What is the volume at STP occupied by:
a- 6.02 x 1023 molecules of NO.
b- 1.806 x 1023 molecules of NH3
35. Determine the number of molecules of the following gases at STP:
a- 15.68 L of carbon dioxide gas.
b- 2240 mL of nitrogen dioxide gas.
36. Arrange the following gases ascendingly according to their volume at STP, 0.5 mole oxygen, 25 g
carbon dioxide, 15.05 x l023 molecules of hydrogen.
(C = 12,O = 16)
37. A sample of water was electrolyzed to produce hydrogen and oxygen gas, as shown in the
electrolysis
 2H 2  O2
reaction: 2H 2O 
a.
If 33.6 liters of gas were produced at STP, how many grams of water were consumed in
the reaction?
b- How many molecules of hydrogen are produced when 11 .9L of oxygen is formed at STP?
38. Calculate the density at STP conditions, in gram per liters, of each of the following gases:
a. CO2
b. NH3
c. Cl2
(C = 12,0 = 16, N = 14, Cl = 35.5,)
39. Calculate the molar masses for gases of the following densities at STP:
a-1.161g/L
b-1.70g/L
c- 1.25g/L
40.
41.
42.
43.
Calculate the density of a gas at STP, given that 0.5 mole of the gas weighs 8g.
Determine the concentration of 0.7 mole of sodium hydroxide in 700 milliliters water.
How many moles in 300 milliliters of a 0.7 molar sodium chloride solution?
Two moles of potassium hydroxide were dissolved in water to form 5M solution What is the
volume of the solution?
44. How many moles of lead chromate, PbCrO4 can be produced by addition excess sodium
chromate, Na2CrO4 to 25 mL of a 0.493M solution of lead (II) nitrate, Pb(NO3)2
(Pb = 207, Cr = 52, 0 = 16, Na = 23)
Pb( NO3 )2  Na2CrO4 
 2NaNO3  PbCrO4
45. Calcium carbonate dissolves in acidic solutions as shown in the equation below:
CaCO3  2HNO3 
 Ca( NO3 )2  H2O  CO2
If excess of CaCO3 is added to 0.250 liters of a 2.00 molar HNO3 solution, what is the maximum
volume of CO2 gas that could be produced at standard temperature and pressure?
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46. A quantity of sodium peroxide (Na2O2) is added to water and the following reaction occurs.
2Na2O2 + 2H2O ------- 4NaOH + O2
If 70 mL of oxygen gas (at STP) and 150mL of sodium hydroxide solution are produced, then
what is the molarity of the sodium hydroxide solution? (Na=23,O=16,H=1)
47. A quantity of lithium nitride (Li3N) is added to water the following reaction occurs.
Li3N + 3HOH --------- 3LiOH + NH3
If 100 mL of ammonia gas (at STP) and 255mL of lithium hydroxide solution produced, then what
is the molarity of the lithium hydroxide solution?
48. Calculate the number of grams of nitric acid needed to prepare 350mL of a 6.00M nitric acid
solution.
(N = 14, I = 1,O = 16)
49. Calculate the molarity of ascorbic acid, C6H8O6 (vitamin C), solution prepared by dissolving 1.80 g
in enough amount of water to prepare 125mL of solution. (C = 12, H= 1, O = 16)
50. What volume, in ml, of a 0.48 M solution is required to provide 9.1 g of MgCI2
(Mg = 24, Cl = 35.5)
51. What mass of the active metal magnesium is required to react exactly with the hydrochloric acid
in a 125.0 mL sample of a 0.2110 M solution of HCI?
Mg + 2HCl ------- MgCl2 + H2
(Mg = 24)
+
52. How many hydrogen ions (H ) are found in one mole of HCI acid? and what is the mass of these
ions? (H = 1)
53. How many moles of H+ ions are there in 1 L of a 5M solution of HCI?
54. If 52 grams of Ba(NO3)2 (molar mass 260 grams) are completely dissolved in 500 milliliters of
distilled water, then what are the concentrations of the barium and nitrate ions?
55. What is the molar concentration of all ions in a 0.02 M aqueous solution of lead nitrate
Pb(No3)2?
56. How many grams of NaOH are needed to make 100g of a 5% solution of NaOH?
57. How many grams of H2SO4 are in 1000gm of a 10% solution?
58. What is the mass percent of oxygen in one mole of Ca(NO3)2 (Ca = 40, N = 14,0 = 16)
59. A copper ore contains 13.22 % by mass CuCO3 How many tons of the ore are required to
produce 227.27 Kg of Cu metal?
(Cu = 63.5, C= 12, O=16)
2CuCO3 ----------- 2Cu + 2CO2 + O2
60. Silver metal can be recovered from an ore containing silver carbonate (Ag2CO3) by
decomposition reaction 2Ag2CO3 ----------- 4Ag + 2CO2 + O2
What mass of silver ore, in tons, is needed to prepare 226.8 Kg of silver if the ore is 24.21% by
mass silver carbonate? Assume complete decomposition of the silver carbonate.
(Ag=108,C=12,0=16)
61. Adipic acid, H2C6H8O4 [ (HCOO(CH2)4COOH),is a raw material used for the production of nylon. It
 2H 2C6 H8O4  2H 2O
is made commercially by oxidation of cyclohexane 2C6 H12  5O2 
a- In one of these reactions, 25.0g of cyclohexane were completely consumed. What is the
expected (theoretical) mass of adipic acid?
b- If the actual mass of adipic acid in the previous reaction is 33.5g, what is the percent yield of
adipic acid?
(C = 12, H = 1,O = 16)
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62. When HgO is heated, it decomposes into mercury and O2. If 62.7 g of mercury is actually
obtained from the decomposition of 75.8 g of the oxide, what is the percent yield of mercury?
(Hg= 200.6, O = 16)
63. Copper metal is extracted from copper (I) sulphide ore (Cu2S)
First, by roasting it in a limited amount of atmospheric oxygen gas in order to get rid partially of
sulphur dioxide and copper (II) oxide is obtained. Cu2S +2O2 ---------- 2CuO+SO2
Then, the produced copper (II) oxide is reduced by the remaining copper(l) sulphide ore
2CuO + Cu2S -------- 4Cu+SO2
Calculate the mass of copper (I) sulphide ore, which contains 50 % impurities, needed to
produce 3 tons of copper metal. (Cu = 63.5, S = 32)
64. Fish generally need an oxygen concentration in water of at least 5 ppm for survival. Will river
water that contains 7 mg of oxygen per liter contain sufficient oxygen to sustain fish life? (1Lof
water Weighs 1 Kg).
65. A carbon dioxide concentration in water of 200 ppm or higher is lethal to fish. Will river water
that contains 0.62 g of dissolved carbon dioxide per 2 Kg be toxic to fish
66. A3Kg of a mixture containing 0.6g of sodium carbonate. Calculate the concentration of sodium
carbonate in ppm.
67. In the laboratory, 20.0 mL of an aqueous solution of calcium hydroxide, Ca(OH)2 was used in a
titration. A drop of phenolphthalein was added to it to indicate the end point. The solution
turned colourless after 20.0 mL of standard solution of O.050M HCI solution was added.What
was the molarity of the Ca(OH)2
68. What volume, in liter, of 0.0385M HCI is required to react with 22.0mL of 0.130M NaOH?
69. How many milliliters of 0.3M Ba(OH)2 solution are required to neutralize 45mL of 0.51M H2SO4
solution?
70. Find out the mass of sodium hydroxide that presents in 25mL solution which consumes, by
titration, 15mL of 0.1M of hydrochloric acid solution.
(Na = 23,0 = 16, H = 1)
71. A 15.3mL of potassium hydroxide was titrated with 22.3mL of 0.025M sulphuric acid.
a- What was the molarity of potassium hydroxide?
b- What was the mass of potassium hydroxide? (K = 39,O = 16, H = 1)
72. A 0.439 calcium hydroxide dissolved in its solution was neutralized with 11 8mL of sulphuric
acid. What was the molarity of sulphuric acid? (Ca= 40,O = 16, H = 1)
73. A 1.25g sample of impure Na is found to react completely in the 70 mL of 0.125M HCI. The
 2NaCl  CO2  H 2O
equation for the reaction is Na2CO3  2HCl 
What was the mass percent of sodium carbonate in the impure sample?
(Na=23, C = 12,0=16, H = 1, Cl = 35.5)
74. A 0.53g of a mixture of solid substance containing sodium hydroxide and sodium chloride was
titrated with 0.25M hydrochloric acid. The complete reaction takes place by consumption of
15mL of the acid. Calculate the percentage of sodium hydroxide in the mixture
(Na = 23,0 = 16, H = 1)
75. A 1 .7g of a mixture of solid substance containing potassium hydroxide and potassium sulphate
was titrated with 0.06M sulphuric acid. The complete reaction takes place by consumption of
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76.
77.
78.
79.
80.
138mL of the acid. Calculate the percentage of potassium sulphate in the mixture.
(K =39 ,O = 16, H= 1)
A 1.023 grams of hydrated cobalt (II) sulphate (CoSO4 — XH2O) was strongly heated until a
constant mass 0.603 grams. Calculate the percentage of water of crystallization of the hydrated
cobalt (II) sulphate, then calculate the number of water molecules of crystallization and write
the molecular formula of the hydrated cobalt II sulphate salt. (Co=59
S= 32 O=16 H=1)
Find the percentage of water of crystallization and the molecular formula of the hydrated iron
(II) chloride crystals (FeCl2. XH2O) from the following givens:
Mass of hydrated sample of iron (II) chloride = 3.768grams. Mass of anhydrous sample of iron
(II) chloride = 2.405 grams. (Fe= 56, Cl= 35.5 , H=1 , O=16)
A 1.687 grams of hydrated magnesium sulphate salt (MgSO4 – XH2O) was heated until a
constant mass of 0.824grams.
a- Calculate the percentage of water of crystallization of the hydrated magnesium sulphate.
b- Find out the number of water molecules of crystallization and write the molecular formula of
the salt.(Mg = 24, S = 32, O=16, H=1)
Find the molecular formula of washing soda crystals (hydrated sodium carbonate) given that,
the mass of the hydrated crystals before heating is 5 grams and after strong heating and
constant mass is 1.853 grams. (Na=23,C=12,O=16,H=1)
Magnesium, calcium and zinc all react in the hydrochloric acid as follows
M ( S )  2HCl( Aq ) 
 MCl2( aq )  H 2 (where M represents any of these metals)
A sample of one of these metals reacts completely with the acid in 27.9 mL of 2.48 M HCI, and
the resulting solution is evaporated to dryness. The residue MCI2 has a mass of 4.72 g. What is
identity of the metal used? (Cl =35.5, Mg =24, Ca=40, Zn=65.)
81. Iron, nickel and tin all react in the hydrochloric acid as follows (where M represents of these
 MCl2( aq )  H 2
metals) M ( S )  2HCl( Aq ) 
A sample of one of these metals reacts completely with the acid in 34.2 mL of 4 M HCI, and the
resulting solution is evaporated to dryness. The residue MCI2 has a mass of 8.87g. What is the
identity of the metal used? (Cl = 35.5, Fe = 56, Ni = 58.7, Sn = 118.7)
82. Calculate the mass of copper sulphate required to precipitate 5 grams of copper hydroxide
according to the following equation:
CuSO4 + 2NaOH ----------- >Cu(OH)2 + Na2SO4 (Cu = 63.5, S = 32,O = 16, H = 1)
83. Sodium hydroxide solution was added to iron (II) sulphate solution, the precipitate, iron (II)
hydroxide was separated by filtration then drying, its mass was 2.3 grams. Calculate the mass of
iron (II) sulphate in its solution.
(Fe = 56, S = 32, O= 16, H= 1)
84. Calculate the number of moles of silver chloride (AgCI) precipitated from the reaction of 5.85g
sodium chloride (NaCI) with 17 grams of silver nitrate (AgNO3) (Ag = 108, Na = 23, Cl = 35.5)
85. HCI (aq) + AgNO3 -------- AgCl(S) + HNO3. One half liter of a 0.20 molar HCI solution is mixed with
a sufficient amount of AgNO3 solution. A reaction occurs forming a precipitate as shown above.If
the reaction: goes to completion, then what is the mass of AgCI produced?
(Ag = 108, N = 14, O = 16, Cl = 35.5, H = 1)
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86. How many milliliters of barium chloride solution (containing 30g of BaCl2 in one liter) are needed
to precipitate the sulphate ions from a solution containing 0.5 grams of potassium sulphate?
BaCI2. 2H2O + K2SO4 ------------- 2KCI + 2H2O + BaSO4
(Cl = 35.5, Ba = 137,S = 32, K = 39, O= 16, H = 1)
87. A three gram portion of impure barium chloride was dissolved in water. Excess of sodium
sulphate solution was added to precipitate 2 grams of barium sulphate. Calculate the % of
barium in the sample. (Ba = 137, S = 32 , O = 16)
WITH MANY THANKS MR. KHALED NASR
Tel: 0105679458
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