Explore topic-wise InterviewSolutions in .

(A) Ozone as an oxidising agent : Since ozone decomposes to liberate nascent oxygen, it is a powerful oxidising agent next to fluorine.

O_3(g) → O_2(g) + O

For example :

It oxidises lead sulphide (PbS) to lead sulphate (PbSO₄) changing the oxidation state of S from – 2 to +6.

PbS_(s) + 4O_3(g) → PbSO_(s) + 4O_2(g)

Potassium iodide, KI is oxidised to iodine, I₃ in the solution. 

2KI_(aq) + H₃O_(I) + O_3(g) → 2KOH_(aq) + I_2(s) + O_2(g)

Ozone oxidises nitrogen oxide to nitrogen dioxide.

NO_(g) + O_3(g)  → NO_2(g) + O_2(g)

(B) Ozone as a reducing agent : Ozone reduces peroxides (O^1-) to oxides (O^2-).

Ozone reduces barium peroxide,BaO₂ to barium oxide, BaO.

Ozone reduces hydrogen peroxide,H₂O₂ to water, H₂O.

H₂O₂ + O₃ → H₂O + 2O₂

A. CCl₄

B. CO

C. CH₄

Due to increase in size from F to I, H-X bond length increases and thus bond energy decreases.

It is because halogens absorb light energy from visible region to excite the electron and radiate energy corresponding to its complemantry colour.

HI > HBr > HCl > HF

3Cl₂ + 6NaOH → 5NaCl + NaClO₃ + 3H₂O

Yes, chlorine from zero oxidation state is changed to –1 and +5 oxidation states.

Physical properties of dihydrogen:

• Dihydrogen is a colourless, tasteless and odourless gas.
• It bums with a pale blue flame.
• It is a nonpolar and water-insoluble gas.
• It is lighter than air.

Option : (c) amphoteric oxide

A. i. Both gallium (Ga) and thallium (Tl) belong to group 13.

ii. Ga is lighter element compared to thallium Tl. 

Therefore,

Its +3 oxidation state is stable. 

Thus, 

Ga+ loses two electrons and get oxidized to Ga³⁺. 

Hence, 

Ga+ salts are better reducing agent.

iii. Thallium is a heavy element. 

Therefore, due to the inert pair effect, 

Tl forms stable compounds in +1 oxidation state. 

Thus,

Tl³⁺ salts get easily reduced to Tl¹⁺ by accepting two electrons. 

Hence,

Tl³⁺ salts are better oxidizing agent.

[Note : This question is modified so as to apply the appropriate textual concept.]

B. i. Pb has electronic configuration [Xe] 4f¹⁴5d¹⁰6s²6p².

ii. Due to poor shielding of 6s² electrons by inner d and f electrons, it is difficult to remove 6s² electrons (inert pair).

iii. Thus, due to inert pair effect, 

+2 oxidation state is more stable than +4 oxidation state. 

Hence, 

PbCl₄ is less stable than PbCl₂.

Option : (a) He

Option : (a) Argon

The uses of dioxygen are as follows :

• Dioxygen is essential for sustaining life. It is used in hospitals for artificial respiration. 
• It is used in oxy-hydrogen (2800°C) and oxyacetylene (3200°C) torches used for cutting and welding metals. 
• Oxygen cylinders are used in hospitals, for high altitude flying and in mountaineering. 
• It is used in the combustion of fuels. In rockets, hydrazine in oxygen is used as a fuel as it provides tremendous thrust. 

i. Carbon (C) 

ii. Carbon

iii. Tin (Sn) and lead (Pb) 

iv. Carbon

Option : a. of inert pair effect

Correct option is (C) Thallium

Correct option is (B) two

Option : d. Pb

The general characteristics of interhalogen compounds are as follows :

• In XX'_n, X is the halogen which has larger size and is more electropositive, while X' is the halogen having smaller size and is less electropositive, n is the number of atoms of X' attached to X.
• Interhalogen compounds are named as halogen halides. The more electropositive halogen is named as such and the less electropositive halogen is named as the halide. In ClF, since Cl is larger and more electropositive than F, the interhalogen compound is named as Chlorine monofluoride,
• As the ratio of radii (radius of X : radius of X’ ) between the atoms X and X’ increases, the number of halogen atoms (n) per interhalogen compound also increases.
• The interhalogen compounds have even number of atoms i.e. 2,4,6,8. 

For example, 

ClF₃ has 4 atoms and BrF₅ has 6 atoms.

• The number of X' atoms in the interhalogen compounds are always odd. 
• The properties of interhalogen compounds are generally intermediate between those of the halogens from which they are made.
• The oxidation state of the atom X in XX'_n, is equal to +1, +3, +5, +7 and that of X' is -1.
• Since the electronegativity difference between two different halogens is low, the interhalogen compounds are covalent in nature.
• Interhalogen compounds exist as gases, liquids and solids depending upon their composition. They are volatile and less stable but not explosive.
• They are diamagnetic in nature.
• Since the interhalogen bond (X – X’) is weaker than parent halogens, they are more reactive than halogens. x- l so >oui bruin Timor! N

Interhalogen compounds undergo hydrolysis and form haloacids of lower halogen and oxyacid of higher halogen in interhalogen compounds. 

BrCl + H₂O → HOBr + HCl 

5ICl + 3H₂O → HIO₃ + 5HCl + 2I₂

2ICI₃ + 3H₂O → HIO₃ + 5HCl + ICl

Correct answer is

C. IF₅

Correct answer is

D. F

(i) K_metals>>K _insulators<K_{semiconductors}

Calcium carbonate (CaCO₃) occur naturally in the form of chalk, limestone and marble.

Option : (c) CaOCl₂

• Calcium carbonate in the form of marble is used as building material. 
• It is used in the manufacture of quicklime (CaO) which is the major ingredient of cement.
• A mixture of CaCO₃ and MgCO₃ is used as flux in the extraction of metals from their ores.
• It is required for the manufacture of high-quality paper.
• It is an important ingredient in toothpaste, chewing gum, dietary supplements of calcium and filler in cosmetics.

Let the side of each face be ‘1’ unit say. 

Shapes of different positions (I)                      

Their areas (II) 

1. Front view 

A = (1 × 1) + (1 × 1) + (1 × 1) = 3 Sq. Units 

2. Top view                                                      

A = (1 + 1 + 1) × (1 + 1) = 3 × 2 = 6 Sq. Units 

3. Bottom view                                                

A = (1 + 1 + 1) × (1 + 1) = 3 × 2 = 6 Sq. Units 

Perimeters (III) 

1. —————>        1 + 1 + 1 = 3 Units 

2. —————>        2(l + b) = 2 (3 + 2) = 2 × 5 = 10 Units

3. —————>        2(l + b) = 2 (3 + 2) = 2 × 5 = 10 Units

Correct option is  A) 4

Correct option is (A) 14

In a cube number of edges (E) = 12.

By Euler's relation, we know that

F + V - E = 2

\(\Rightarrow\) F + V = E + 2 = 12+2 = 14

Alternate :- Number of faces in a cube is F = 6,

Number of vertices in a cube is V = 8.

\(\therefore\) F + V = 6+8 = 14

Correct option is  A) 14

1. A) 5

2. C) 9

3. B) 6

4. D) None

Correct option is (D) 12

In a pentagonal pyramid,

Number of Vertices (V) = 6

Number of faces is F = 6

By Euler's formula, we know that

F + V - E = 2

\(\Rightarrow\) E + 2 = F + V

= 6+6 = 12

Correct option is  D) 12

i. In liquids, the distance between the neighbouring particles is less than those in the gases.

ii. In gases, the particles have high energy. They spread out to fill the container and there are no forces to stop them from going apart.

iii. Thus, in gases, the particles are very far apart and the forces of attraction between the particles are extremely weak as compared to liquids.

Hence, gases are more compressible than liquids.

i. In solids, the particles are closely packed together and the forces holding these particles are strong. 

ii. As a result, solids are almost incompressible.

iii. Their volume is not changed by any outside force and their shape remains unchanged even if an external force is applied.

Hence, solids are rigid.

A party has 20 participants. All of them and the host (i.e., 21 persons) can be seated at a circular table in (21 – 1)! = 20! ways.

When two particular participants are seated on either side of the host.

The host takes the chair in 1 way.

These 2 persons can sit on either side of the host in 2! ways.

Once the host occupies his chair, it is not circular permutation more

 The remaining 18 people occupy their chairs in 18! ways.

∴ A total number of arrangements possible if two particular participants are seated on either side of the host = 2! × 18! = 2 × 18!

\(\frac{(n - 1)!}{2}\) = \(\frac{8!}{2}\)

Banks thoroughly analyses the financial requirement of a business, its ability to repay, income tax returns, old and current accounts, profit, etc. If the bank gets satisfied it can lend money in the form of loans, cash credit and overdraft.

To develop some part of Gujarat, the government initiated a project called Sardar Sarovar Yojna. So, the people residing in that area were made to migrate elsewhere. This migration serves as an example of developmental migration.

Correct option is (A) When they do not get expected job and money

People moving to cities from villages for livelihood send a major portion of their income to their families. This in turn improves the standard of living of people living in villages.

Correct option is (C) Migration from rural to urban areas

Strengthen the infrastructural facilities:

• To ensure that the infrastructural facilities like water, road, transportation, communication system, drainage, sanitation, etc. reach each land every person the government should make its system strong. . .
• To take the infrastructure at a much higher letef the Central Government has implemented a plan to convert some cities into smart cities.
• The government should-make efforts to construct houses for slum dwellers. With this objective the Central Government has initiated various. housing schemes for the poor and middle income group people.

Indian Railways was started during British Rule on 16th April, 1853 between Bombay and Thane, a distance of 22 miles a 34 km.

• After independence the administration of railway came into the hands of Indian Government and managed through a separate department.
• Today railway network of India stands to be number one in Asia and number 4 in the world.
• Railway is India’s biggest public enterprise and today more than 14 lakhs people have got employment in it.
• In 2012, 8200 million passengers travelled in Indian Railways and 970 million tonnes of goods were transported by railways.

Importance of railway in India’s economic development:

• Because of occupational dynamism industrialisation and business has become faster.
• Due to increase in speed, safety and comfort level of travel regional dynamisjn of labour has improved.
• The commercialisation of agriculture has been increased.
• India’s foreign trade has developed.
• A new sector – tourism has developed.
• A link for national unity and integrity has developed.
  It has been found that petroleum resources are present in Kadi, Kalol, Ankleshwar, etc. in Gujarat and in Bombay High for offshore drilling platform has been erected.

Steps of encouragement for development 0f railway:

• The work of gauge conversion is made speedy.
• More facilities are being created to make rail travel safer.
• Railway compartments are also being modernised to make passengers feel more comfort.
• Modernisation of railway station is taken up.
• More and more electrification of railway is taking place.
• By increasing the speed of the train, time of travelling

India’s contribution to petroleum production is just 0.4 % of the total.

• Natural gas also is considered to be of petroleum origin. Total gas production in India is only 0.5 % of the total gas of the world.
• Natural gas is increasingly used in the production of electricity and for vehicle operation. Use of gas is considered Environment friendly.

Correct option is (A) Improvement of education facilities in rural areas 

Development of infrastructural facilities in rural areas:

Government should make effort to improve infrastructural facilities such as education, transportation, communication, roads, electricity, irrigation, etc. of smaller towns and cities. Doing so, people will not be forced to migrate to urban areas. This will further reduce the burden on cities and the negative effects of urbanization can be controlled.

• The productivity of a labour is dependent on his health.
• The way education is a means for healthy mind, health services and its infrastructure is a means for physical health of the body.
• National income is directly dependent on the public health.
• If the labour is not healthy he may fall ill frequently which will then adversely affect his productivity and overall production.
• Natural resources can be better utilized and wastage of resources can be stopped if the countrymen are healthy.
• Better health can enable a person to work efficiently. This will then increase his income. Rise in incomes of labour, leads to higher standard of living which in turn boosts economy.

Rural health:

• Even today, 70% of India’s total population lives in villages. Contrary to this only 1/5th of the total number of hospitals of the country are in rural areas. As a result, the rural areas are deprived of necessary medical services. One can see a vast difference between the medical services available in rural and urban areas.
• Rural areas do not have specialists like child specialists (Peadiatrist), specialist for woman (Gynaecologists) anesthetist, eye specialist (Ophthalmologist) like M.D., M.S. and other such highly qualified doctors. Hence, rural population cannot avail these treatments on time in their vicinities.

Correct option is (B) 4.4%

Atoms having same atomic mass and different atomic numbers are known as Isobars.

Example: ⁴⁰₁₈Ar(argon) and ⁴⁰₂₀Ca(calcium)

Both the elements have same atomic mass equal to 40 but different atomic numbers, i.e. argon has atomic number equal to 18 and calcium has atomic number equal to 20.

(B) the ethanoic acid dissolves readily in water