Kill the fear of chemistry
Let prepare for "BOARD EXAMS"
Few of the posts I've made in the recent cover a part of chemistry . This part of chemistry will give you additional matter for your Rocking Success in 10 th Grade.
Give reason :
1 - Why is the size of inert gases are greater than in corresponding period ?
2 - Group 17 elements are strong non-metals ,while group 1 elements are strong
metal.
3 - Metallic character of elements decreases from left to right in a period while it
increases in moving down a group.
4 - Halogens have a high electron affinity.
5 - The reducing power of element increases down in group while decreases in a
period.
6 - Size of atoms progressively becomes smaller when we move from sodium (Na)
to Chlorine(Cl) in the third period of the periodic table.
7 - The size of Cl ion is greater than the size of Cl atom.
8 - Argon atom is bigger than Cl atom.
9 - Ionisation potential of the element is increases across a period.
10 - Alkali metals are good reducing agent.
11 - Nitric acid is not used in the preparation of hydrogen.
11 - Nitric acid is not used in the preparation of hydrogen.
12 - Why covalent compounds are volatile in nature ?
13 - Covalent compounds are insoluble in water where as elctrovalent compounds
are soluble.
14 - Electrovalent compounds are usually hard crystal yet brittle.
15 - Polar covalent compounds conduct electricity .
16 - Carbonic acid gives an acid salt but hydrochloric acid does not.
17 - Dil. HCl acid is stronger than highly concentrated acetic acid.
18 - H3PO3 is not a tribasic acid .
19 - Lead carbonate do not react with dilute HCl .
20 - Nitrogen dioxide is a double acid anhydride.
21 - It is necessary to find out the ratio of reactants required in the preparation of
sodium sulphate.
22 - Fused calcium chloride is used in the preparation of FeCl3?
23 - Anhydrous FeCl3 cannot be prepared by heating hydrated Iron (3) chloride.
24 - Why common salt get wet during the rainy season ?
25 - Why " The number of atoms in a certain volume of hydrogen is twice the number of atoms in the same volume of helium at the same temperature
and pressure".
26 - why "when stating the volume of a gas the pressure and temperature should
also be given."
27 - Why inflating a baloon seems to violate Boyles Law.
28 - Why C - 12 was selected as a unit and masses of other atoms were compared
with it ?
29 - A solution of cane sugar does not conduct electricity , but a solution of soium chloride is agood conductor.
30 - Hydrochloric acid is a good conductor of electricity.
32 - On electrolysis of dilute copper(II) sulphate solution , copper is deposited at the
cathode but no hydrogen gas evolves there.
33 - When a dilute aqueous solution of sodium chloride is electrolysed between platinum electrodes , hydrogen gas is evolved at the cathode but metallic sodium is not deposited.
34 - Zinc can produce hydrogen on reacting with acids but copper can not.
35 - In the electrolysis of acidified water , dilute sulphuric acid is preferred to dilute nitric acid for acidification.
36 - Electrolysis of molten lead bromide is considered to be a reaction in which oxidation and reduction go side by side i.e. redox reaction.
37 - The blue color of aqueous copper sulphate fades when it is electrolysed using platinum electrodes.
38 - Lead bromide undergoes electrolytic dissociation in the molten state but is a non
electrolyte in the solid state.
39 - Aluminium is extracted from its oxide by electrolytic reduction and not by conventional reducing agent.
40 - The ratio of hydrogen and oxygen formed at the cathode and the anode is 2 :1
by volume.
41 - Ammonia is unionised in the gaseous state but in the aqeuous solution , it is a
weak electrolyte.
42 - A graphite anode is preferred to other inert electrodes during electrolysis of fused lead bromide.
43 - For electroplating with silver , silver nitrate is not used as electrolyte.
44 - Carbon tetrachloride is a liquid but does not conduct electricity.
45 - Alkali metals kept in Kerosene oil.
46 - The rate of reaction decreases on moving from potassium to Lead.
47 - Why does metal not occur free in nature.
48 - The highly reactive metals can be used as reducing agents.
49 - Aluminium reacts with acids sulphuric acid and hydrochloric acid but not nitric acid.
50 - In the electrolytic reduction of alumina , the graphite anode is gradually consumed.
51 - Roasting is carried out on sulphide ores and not on carbonate ores.
52 - Carbon can reduce lead oxide but not aluminium oxide.
53 - Electrolytic reduction is done to obtain aluminium.
54 - Zinc is used to cover iron so as to prevent rusting of iron .Why?
55 - A neutral gas other than oxygen which is formed at the anode during electrolysis of fused alumina.
56 - Nitric acid should be stored in aluminium container.
21 - It is necessary to find out the ratio of reactants required in the preparation of
sodium sulphate.
22 - Fused calcium chloride is used in the preparation of FeCl3?
23 - Anhydrous FeCl3 cannot be prepared by heating hydrated Iron (3) chloride.
24 - Why common salt get wet during the rainy season ?
25 - Why " The number of atoms in a certain volume of hydrogen is twice the number of atoms in the same volume of helium at the same temperature
and pressure".
26 - why "when stating the volume of a gas the pressure and temperature should
also be given."
27 - Why inflating a baloon seems to violate Boyles Law.
28 - Why C - 12 was selected as a unit and masses of other atoms were compared
with it ?
29 - A solution of cane sugar does not conduct electricity , but a solution of soium chloride is agood conductor.
30 - Hydrochloric acid is a good conductor of electricity.
32 - On electrolysis of dilute copper(II) sulphate solution , copper is deposited at the
cathode but no hydrogen gas evolves there.
33 - When a dilute aqueous solution of sodium chloride is electrolysed between platinum electrodes , hydrogen gas is evolved at the cathode but metallic sodium is not deposited.
34 - Zinc can produce hydrogen on reacting with acids but copper can not.
35 - In the electrolysis of acidified water , dilute sulphuric acid is preferred to dilute nitric acid for acidification.
36 - Electrolysis of molten lead bromide is considered to be a reaction in which oxidation and reduction go side by side i.e. redox reaction.
37 - The blue color of aqueous copper sulphate fades when it is electrolysed using platinum electrodes.
38 - Lead bromide undergoes electrolytic dissociation in the molten state but is a non
electrolyte in the solid state.
39 - Aluminium is extracted from its oxide by electrolytic reduction and not by conventional reducing agent.
40 - The ratio of hydrogen and oxygen formed at the cathode and the anode is 2 :1
by volume.
41 - Ammonia is unionised in the gaseous state but in the aqeuous solution , it is a
weak electrolyte.
42 - A graphite anode is preferred to other inert electrodes during electrolysis of fused lead bromide.
43 - For electroplating with silver , silver nitrate is not used as electrolyte.
44 - Carbon tetrachloride is a liquid but does not conduct electricity.
45 - Alkali metals kept in Kerosene oil.
46 - The rate of reaction decreases on moving from potassium to Lead.
47 - Why does metal not occur free in nature.
48 - The highly reactive metals can be used as reducing agents.
49 - Aluminium reacts with acids sulphuric acid and hydrochloric acid but not nitric acid.
50 - In the electrolytic reduction of alumina , the graphite anode is gradually consumed.
51 - Roasting is carried out on sulphide ores and not on carbonate ores.
52 - Carbon can reduce lead oxide but not aluminium oxide.
53 - Electrolytic reduction is done to obtain aluminium.
54 - Zinc is used to cover iron so as to prevent rusting of iron .Why?
55 - A neutral gas other than oxygen which is formed at the anode during electrolysis of fused alumina.
56 - Nitric acid should be stored in aluminium container.
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