Chemistry 12th Class
Completion and Balancing of Equations
Complete and balance the following equations:
1. K2MnO4 + Cl2
2. S + HNO3
3. CuSO4 + KI
4. P + HNO3
5. HCl + HNO3
6. Al + NaOH + H2O
7. FeCl3 + H2S
8. CH2 = CH2 + H2O
9. Zn + NaOH
10. Al + H2SO4 (conc)
11. KMnO4 + H2O2
12. AgNO3 + NH3
13. C2H6 + O2
14. Co + NaOH
15. Ag + HNO3
16. C + H2SO4
17. CaH2 + H2O
18. N2 + Al
19. KOH + Al + H2O
20. H2O + Cl2
21. KMnO4
22. HNO3 + Fe
23. HNO3 + Fe
24. HNO3 + C
25. CH3COONa + NaOH
26. CH3MgBr + C2H5OH
27. C2H5Cl + Ag2O
28. HCHO + Ag(NH3)2OH
29. Zn + NaOH
30. CuSo4 + NH3
31. K2Cr2O7 + KCl + H2SO4
32. HC CH + AgNO3
33. C2H6 + Cl2
34. H2SO4(90%) + Zn
35. HNO3 + Zn
36. HNO3 + Zn
37. NaH + C2H5OH
38. Al + H2SO4
39. ZnS + HCl
40. Cu + HNO3
41. HNO3 + NH4OH
42. PbCrO4 + NaOH
43. Co + H2 + NaOH
44. Zn + NaOH
45. Cu + HNO3
46. Cu + HNO3
47. Zn + HNO3
48. S + HNO3
49. Si + HNO3
50. HCl + HNO3
51. Cu + H2SO4
52. NH4Cl + NaOH
53. Cu2O + Cu2S
54. Na2CO3 + SiO2
55. PbO + O2
56. Na2B4O7 + H2O
57. AgNO3 + NaOH
58. Ca(OH)2 + Cl2
59. NaOH + H2O + Al
60. Al + Fe2O3
61. Al + HCl
62. CH CH + H2O + [O]
63. CH CH + 4[O]
64. H-HO + [Ag(NH3)2]OH
65. H-CHO + Cu(OH)2 + NaOH
66. CH3-HO + [Ag(NH3)2]OH
67. C2H5 – Mg – Cl + H+OH-
68. C2H5OH + Na
69. C2H5OH + C2H5-COOH
70. HCHO + NaOH
71. CH3-CO-CH3 + I2 + Na2CO3
72. H2S + Br2
73. H3BO3 + NaOH
74. SO2 + Cl2
Fill in the Blanks
Five Year Papers
1. Plastics are polymers of ______.
2. From crude oil, additional quantity of petrol is obtained by ______process.
3. Tertiary alkyl halides react by ______reaction mechanism.
4. ______period is incomplete.
5. Elements, which follow actinium, are called ______elements.
6. Ionic hydrides are also called ______.
7. Compounds with the general formula CnH2n + 2O are called ______.
8. Resorcinol is not an alcohol but a ______.
9. A ketone contianing different alkyl radicals is called ______ketone.
10. The hydrolysis of fats and oils with a strong alkali is called ______.
11. ______is active in the stomach of young children.
12. The chemical name of Lunar caustic is ______.
13. Aluminium resists corrosion due to the formation of ______.
14. EDTA is a ______ligand.
15. The chemical formula of rust is ______.
16. Sub-Group B elements are called ______elements.
17. The hybridization of carbon in graphite is ______.
18. The chemical name of vitamin B2 is ______.
19. The reactions between metallic sodium and alkyl halides are called ______reaction.
20. The fractional distillation of crude petroleum yields only ______% petrol.
21. Starch and Cellulose are the examples of ______carbohydrates.
22. AgCl dissolves in ammonia to form ______.
Chapter 1
Periodic Classification of Elements
1. In 1913 Moseley, A British physicist, found that a ______is the fundamental property of an atom.
2. In the modern Periodic table recommended by the International Union of Pure and Applied Chemistry (IUPAC) in 1982, the elements are arranged in the ascending order of ______.
3. Horizontal rows of elements in the periodic table are called ______.
4. The vertical columns of elements arranged in the Periodic table are called ______.
5. In the Modern Periodic Table there are ______periods.
6. The first period of Modern Periodic Table contains ______elements.
7. Hydrogen lies in ______Period.
8. Helium lies in ______Period.
9. All the elements belonging to the second period are ______.
10. Second period contains ______elements.
11. The elements of the second period of the modern Periodic table are ______.
12. Third period of periodic table contains ______elements.
13. The elements of the fourth period of the modern periodic table are ______.
14. Fourth period of Modern Periodic Table contains ______elements.
15. Fifth period of Modern Periodic Table contains ______elements.
16. Those elements, which have ‘d’ orbitals in the process of completion in the form of ions or atoms, are called ______.
17. Elements in IB group are called ______.
18. Those elements, which involve ‘s’ orbital filling in their valence shells, are called ______.
19. The sixth period of Modern Periodic Table contains ______elements.
20. The longest period of modern Periodic Table is ______.
21. The eight ‘s’ and ‘p’ block elements in the 4th and 5th periods are known as ______.
22. The elements of group IA and IIA are classified as ______elements.
23. The seventh period of modern Periodic table contains ______elements.
24. The elements on the right hand side of the Periodic table are called ______.
25. The outer most shell involved in chemical bonding are called ______.
26. The number of electrons in the outermost or valence shells is called ______.
27. Na2O is strongly ______in nature.
28. Cl2O7 is strongly ______in nature.
29. Greater the electronegativity of an element, stronger is the ______character of its oxide.
30. In case of transition elements, the last electrons are received by ______.
31. Elements in group IB, IIB through VIIB are known as ______.
32. Elements in group IB, IIB through VIIB are known as ______.
33. Elements in the group VI A and ______are the most active non-metals.
34. The correct order of second ionization potential of carbon, nitrogen, oxygen and fluorine is ______.
35. The elements having seven valence electrons are known as ______.
36. The elements of group IIIA to VIIA are called ______.
37. Maximum number of electrons present in sixth period is ______.
38. The elements of group VIIIA are called ______.
39. In case of inner transition elements the last electrons are received by ______.
40. In case of outer transition elements the last electron are received by ______.
Chapter 2
Hydrogen
1. Hydrogen was first prepared by Cavendish in 1766 by the action of ______.
2. Hydrogen is evolved by the action of cold diluted HNO3 on ______.
3. Hydrogen is found in nature in combined state. The most abundant compound of hydrogen is ______.
4. The electronic configuration of hydrogen atom is ______.
5. Hydrogen forms slat like hydrides with the elements of ______.
6. Hydrogen forms interstitial hydrides with the elements of ______.
7. An example of covalent hydride is ______.
8. Alkali metals need ______electron to complete their outermost shells.
9. The number of isotopes of hydrogen is ______.
10.1H1 is symbol of ______.
11.1H2 is the symbol of ______.
12.1H3 is the symbol of ______.
13. The number of neutrons in the nuclei of tritium atom is ______.
14. The number of neutrons in the nucleus of protium is ______.
15. The mass number of deutrium is ______.
16. Tritium is present to the extent of one atom in ______atoms.
17. Chemical formula of heavy water is ______.
18. Hydrogen is obtained industrially as a by-product during electrolysis of ______.
19. Hydrogen is commercially prepared by the thermal decomposition of
20. Hydrogen burns in air with ______flame.
21. Density of hydrogen is about of 1/14th of that of ______.
22. The electronegativity of hydrogen is ______.
23. The bond energy of hydrogen is ______.
24. Hydrogen liquefies at ______.
25. Hydrogen freezes at ______.
26. The symbol of hydride ion is ______.
27. Hydrogen burns on ignition in the presence of oxygen to produce ______.
28. Hydrogen reacts on heating with P directly to form ______.
29. The hydrides formed by the combination of non-metals of groups IVA, VA, VIA and VIIA with hydrogen are called ______.
30. LiAlH4 is an example of ______.
31. The atomic weight of heavy hydrogen is ______.
32. ______is the commonest gas in the atmosphere.
33. The element, which does not make salt like hydride is ______.
Chapter 3
S-Block Elements
1. In s-block elements the outermost orbitals are filled with ______electrons at the outer most.
2. S-block elements consist of ______.
3. The colour of the flame of potassium is ______.
4. On bunsen flame sodium gives ______.
5. On bunsen flame Potassium gives ______.
6. On bunsen flame Cesium gives ______.
7. On bunsen flame Calsium gives ______.
8. On bunsen flame Strontium gives ______.
9. On bunsen flame Barium gives ______.
10. Alkaline earth metals are relatively ______reactive than alkali metals.
11. An apparatus used for commercial preparation of sodium is named as ______.
12. Baking soda is also called ______.
13. The radius of K-atom is 2.31A. The radius of K+ will be ______.
14. Bicarbonate of alkali metals and alkaline earth metals are formed by passing ______through a solution of the carbonates of alkali metals or a suspension of carbonates of alkaline earth metals in water.
15. Metallic sodium was first obtained by Sir H. Davy in 1807 by the electrolysis of fused ______.
16. Gay Lussac and Thenard in 1811 prepared sodium by reducing sodium hydroxide with ______.
17. The process in which sodium was prepared by distilling sodium carbonate with carbon and a small amount of chalk as a catalyst was introduced by ______.
18. Down’s cell is used for the production of ______.
19. The density of sodium metal is ______.
20. Melting point of sodium is ______.
21. Boiling point of sodium is ______.
22. The annual consumption of NaCl is about ______.
23. ______percentage of NaCl is present in sea water.
24. ______percentage of NaCl or Common salt is present in rock salt.
25. Sodium carbonate is generally called ______.
26. Sodium carbonate is prepared by ______.
27. Aqueous solution of sodium carbonate on heating gives sodium carbonate and ______.
28. ______is medically used for the treatment of hyperacidity in the stomach.
29. In firge extinguishers ______is used as a source of carbon dioxide.
30. Mixture of sodium bicarbonate and crystals of vegetable acids, e.g. tartaric acid or citric acid is known as ______.
31. Anhydrous sodium carbonate is called ______.
32. Industrial use of sodium carbonate is in the manufacture of ______.
33. ______is used in the smelting of iron ores of high sulphur content.
34. Sodium Hydroxide is manufactured on large scale by electrolysis of aqueous solution of ______.
35. Nelson’s cells is used for the manufacture of ______.
36. Castner-Kellner Process is used for the production of ______on industrial scale.
37. The melting point of NaOH is ______.
38. NaOH decomposes into its elements at about ______.
39. Bleaching powder is manufactured by treating lime with chlorine in ______.
40. The colour of bleaching powder is ______.
41. Bleaching powder smells strongly like ______.
42. When bleaching powder is treated with strong solution of ammonia, ______gas is evolved.
43. Calsium sulphate occurs in nature as dihydrate salt called ______.
44. Gypsum can be prepared by the action of dilute sulphuric acid on ______.
45. At ______temperature gypsum loses its three fourth of water.
46. Gypsum is sparingly soluble in water. Its solubility increases with rising temperature up to ______.
47. Magnesium sulphate is usually sold as hydrated salt called ______.
48. Epsom salt is prepared from magnesite MgCO3 on boiling with dilute ______.
49. Epsom salt loses six molecules of water at ______.
50. Epsom salt becomes anhydous at ______.
51. Epsom salt is converted into magnesium oxide by heating it with carbon at about ______.
52. ______is used in medicine as purgative.
Chapter 4
P-Block Elements
1. The elements, which belong to III-A group to VIII-A group, are called ______.
2. In p-block elements the metallic character ______down the group.
3. In p-block elements the orbital in the process of completion is ______.
4. Crystalline boron is a hard substance which is ______in colour.
5. Out of all the elements of group IIIA, the highest Ionization potential is for ______.
6. Boron possesses close resemblance with ______.
7. Orthoboric acid is prepared by the acidification of hot concentrated solution of borax with calculated quantity of ______.
8. In the Hall-Berou.t process for producing aluminium the substance produced at the cathode is ______.
9. Hydrogen gas many be produced by the reaction of aluminium with a concentrated solution of ______.
10. The most widely distributed element in the earth’s crust after oxygen and silicon is ______.
11. Aluminium resists corrosion due to the formation of a coat of ______.
12. Hall’s Process is used for the production of ______.
13. Duralum is an alloy which contains Mg + Cu + ______+ Mn.
14. The group IV-A of the periodic table consists of ______.
15. Diamond has a high refractive index of ______.
16. At 700C graphite burns in air to form ______.
17. Red lead is commonly known as ______.
18. ______is the product of thermal decomposition of sodium bicarbonate.
19. Lead Monoxide is a yellow powder and also called ______.
20. Nitrogen, phosphorus, arsenic, antimony and bismuth are the members of the group ______.
21. All members of group VA exhibit maximum oxidation state of ______.
22. The shape of diamond is ______.
23. On an industrial scale nitric acid is prepared by ______.
24. Poisonous gas present in the exhaust fumes of car is ______.
25. The boiling point of nitric acid is ______.
26. The freezing point of nitric acid is ______.
27. Oxygen, sulphur, selenium, tellurium and polonium are the members of group ______.
28. The first four members of the group VI-A are collectively called ______.
29. There are ______electrons in the valence shell of elements of group VI-A.
30. The maximum valency of oxygen is ______.
31. Oxygen has ______allotropic forms.
32. The transition temperature of sulphur is ______.
33. X-rays analysis shows that ______sulphur consists of chains of sulphur atoms.
34. The purest H2S is obtained by passing vapours of sulphur and hydrogen over finely divided ______at 450C.
35. ______was first prepared in the laboratory by Jabir Bin Hayyan.
36. ______is called king of chemicals.
37. Lead Chamber process is used for the preparation of ______.
38. Contact Process is used for the production of ______.
39. ______is called Oleum.
40. Freezing point of pure sulphuric acid is ______.
41. Dilute sulphuric acid dissolves many metals with the evolution of ______and the corresponding sulphates are formed.
42. Formic acid is converted into carbon monoxide by the action of concentrated ______and heating.
43. Gases such as oxygen, hydrogen, carbon dioxide, chlorine and sulphur dioxide are often dried by bubbling them through ______.
44. Concentrated sulphuric acid absorbs sulphur trioxide forming ______.
45. Carbon is oxidized to ______in the presence of sulphuric acid.
46. In a process called pickling the metal sheets are soaked in ______to remove rust or by chemical action.
47. Phosphine may be produced by the action of water on ______.
48. In the refining of petroleum, ______is employed to remove tarry materials and sulphur compound.
49. In the Ostwald process, the substance which is used to oxidize NH3 is ______.
50. In the periodic table, halogens, namely fluorine, chlorine, bromine, iodine and astatine are placed in group ______.
51. The brown gas formed when metals reduce HNO3 is ______.
52. ______is used as catalyst in the Contact Process.
Chapter 5
Transition Elements
1. Annual production of antimony being mined in Pakistan is ______.
2. Annual production of Orchro being mined in Pakistan is ______.
3. Annual production of Chromite being mined in Pakistan is ______.
4. Annual production of manganese being mined in Pakistan is ______.
5. Transition elements other than Sc, Y and Ti have density above ______.
6. Due to d-d transition of electrons, Cu2+ ion appears ______in colour.
7. The colour of Fe3+ ion is ______.
8. The colour of Fe2+ ion is ______.
9. The colour of Cr3+ ion is ______.
10. The colour of Mn3+ ion is ______.
11. The colour of Mn2+ ion is ______.
12. The colour of the fmale of potassium is ______.
13. The magnetic moment is related to the number of unpaired electron ‘n’ by the equation ______.
14. All the 3-d series elements show an oxidation state of ______in addition to higher oxidation states except Sc.
15. The majority of transition metal’s ion complexes contain ______ligands surrounding the central octrahedrally.
16. Copper is known since ______.
17. In Pakistan copper mines at Saindak in ______were first discovered in 1962.
18. It is estimated that the Saindak mines will yield an annual production of ______tones of copper from its sulphide ore for a period of 16 years on the commencement of production.
19. ______percentage of total copper metal is obtained from sulphide ore.
20. The colour of copper is ______.
21. Copper becomes ______when it is heated.
22. Copper melts at ______C.
23. Cu2O is ______in colour.
24. The colour of CuO oxide is ______.
25. When copper is heated in air, then CuO + ______are formed.
26. Bronze contains ______% Cu and 10% Sn.
27. ______is prepared in the laboratory by the action of dilute sulphuric acid on cupric oxide or cupric carbonate.
28. ______is prepared by dissolving metallic silver in warm dilute nitric acid.
29. The highest common oxidation state of chromium is ______.
30. ______is prepared in the laboratory by the addition of potassium chloride to hot concentrated solution of sodium dichromate.
31. ______is used an an indicator in silver nitrate titration for the estimation of halide ions.
32. Potassium permanganate oxidizes acid in presence of dilute ______.
33. ______is used as a disinfectant for purification of water.
34. ______is used in bleaching paper pulp.
35. The rusting of iron is catalyzed by ______.
36. Conversion of any metal into its oxide by the action of environment is called ______.
37. Rusting of iron is an example of ______.
38. Aluminium resists the process of corrosion due to the formation of ______.
39. An alloy of iron, which contains chromium 18%, nickel 8% and carbon 0.18% is ______.
40. The black image on an exposed and developed photographic film is composed of ______.
41. In photography printing is accomplished by using an emulsion of ______.
42. All transition elements are ______.
43. Iron rust has the composition of ______.
44. When hydrated, Fe2+ ions are ______.
Chapter 6
Organic Chemistry
1. The main component of coal is ______.
2. When coal is heated in the absence of air, temperature ranging from ______, it is converted into coke, coal gas and coal tar.
3. The octane number of gasoline may also be increased by ading ______as knoc inhibitor.
4. In Houdry process the breaking down of long-chain hydrocarbons is accelerated in the presence of a catalyst, made up of a mixture of ______.
5. The process of cracking takes place between temperature ______.
6. Molecular formula of ethers is ______.
7. Alkanes have general formula ______.
8. How many isomers can be obtained from the alkane C6H14.
9. Each alkane differs from its neighbours by ______.
10. The structural formula of ethane is ______.
11. Alkenes have general formula ______.
12. Alkyl halides have general formula ______.
13. On destructive distillation of 1000 kg of coal amount of coal tar formed is ______.
14. Natural gas consist of methane ______.
15. An alkane forms isomers if the number of least carbon atoms is ______.
16. The functional group of alkyle halids is ______.
17. The formula of alkane is ______.
18. The functional group o primary amines is ______.
19. The functional group of ether is ______.
20. The functional group of primary alcohol is ______.
21. The formula of methanol is ______.
22. The formula of ethanol is ______.
23. The formula of propanal is ______.
24. The formula of butanal is ______.
25. Formula of formic acid is ______.
26. The formula of acetic acid is ______.
27. The formula of propnoic acid is ______.
28. The formula of butyric acid is ______.
29. The formula of valeric acid is ______.
30. The formula of capric acid is ______.
31. Phenyl group is represented by ______.
32. The molecular formula of ethane is ______.
Chapter 7
Hydrocarbons
1. An example of alkane is ______.
2. ______is the smallest hydrocarbon.
3. Natural gas consists of about ______% of methane.
4. A reaction catalyzed by the presence of ______is called a photochemical reaction.
5. C2H2 reacts with HCl to produce ______.
6. ______is used as catalyst in the oxidation of methane.
7. Methane reacts with superheated steam, on passing through hot tubes containing a ______catalyst to yield carbon monoxide and hydrogen.
8. In methane H – C – H bond angles are ______.
9. The structural formula of ethylene is ______.
10. ______is called ozone.
11. When ethene is passed through a dilute alkaline solution of KMnO4, the pink colour of the solution ______.
12. ______reagent distinguishes ethylene from acetylene.
13. ______polymerizes at 100 atmosphere pressure and 400C to give polyethylene.
14. The polyethene produced in the presence of ______and titanium tetrachloride as catalyst, shows improvement in its properties such as higher softening temperature, low permeability and greater rigidity.
15. ______is called Dutch Liquid.
16. General formula of alkynes is ______.
17. ______is called Acetylene.
18. Carboxylic acids combine with acetylene in the presence of ______as catalyst, forming vinyl esters and the reaction is termed as Vinylation.
19. When a mixture of acetylene and nitrogen is submitted to an electric discharge, it forms ______.
20. When acetylene is passed through a copper tube at about 300C it polymerizes to ______.
21. The brand of synthetic rubber is made by Polymerization of ______.
22. The process in which orbitals of different energies and shapes mix with each other to give equivalent hybrid orbital is called ______.
23. The sp3 signifies that each sp3 orbital is made up of s and p orbitals in the ratio of ______.
24. A molecule of methane has ______sigma bond(s).
25. A molecule of ethane has ______sigma bond(s).
26. The sp3 hybridization occurs when carbon is bonded to ______other atoms.
27. Sp2 hybrid orbitals are composed of s and p orbitals in the ratio of ______.
28. ______bond is weaker.
Chapter 9
Organic Compounds
1. The general formula of alcohol is ______.
2. The general formula of aldehyde is ______.
3. Alcoholic fermentation is brought out by the action of ______.
4. The general formula of carboxylic acid is ______.
5. The general formula of esters is ______.
6. The general formula of ketone is ______.
7. The general formula of ether is ______.
8. The general formula of phenol is ______.
9. Methyl alcohol is used as the starting matrial in the manufacture of ______.
10. The formula of ethyl alcohol is ______.
11. To start the reversibility Estrification we use concentrated ______used as absorbent of water produced during the reaction.
12. Dehydration means removal of ______.
13. The compound formed when silver powder is ehated with chloform is ______.
14. ______is used as a fuel for internal combustion engines in many European countries and Brazil.
15. The formula of formaldehyde is ______.
16. The derivatives of carboxylic acids are obtained by replacing the –OH group of the carboxylic group with –OH and ______.
17. The formula of Fehling’s solution is ______.
18. The formula of Iodoform is ______.
19. Melting point of Phenol is ______.
20. Boiling point of Phenol is ______.
21. Phenol when treated with ______, yields both ortho and para sulphonic acids.
22. General formula of Grignard’s Reagent is ______.
23. The formula of Cyanogen chloride is ______.
24. The formula of Chloramine is ______.
Multiple Choice Questions
Five Year Papers
1. On passing steam over red-hot coal we get ______.