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In NH₃ molecule there are are four electron pairs (three bond pairs and one lone pair) .These four electron pairs adopt tetrahedral geometry but due to the repulsion by lone pair the bond decreases to 107⁰ from 109.5⁰ and hence the geometry of ammonia is regarded as pryamidal.

This is because NO₂ ⁺ has no lone pair of e-, and hence its linear.NO₂ has one unshared e- while NO₂ has one unshared e- pair.Greater the repulsion on N-O bond in case of NO₂ ^- than in case of NO₂.

At high altitude as the atmospheric pressure is low , the air is less dense. As a result less oxygen is available for breathing . 

Screening effect. The inner electrons between valence electron and nucleus shield the valence electrons from nucleus; it is called shielding effect.

The temperature at which the real gas obeys ideal gas law for an appreciable range of pressure is called Boyle’s point.

In SO₂ molecule there are three electron pairs .the three electron pairs should acquire trigonal planar arrangement with bond angle 120 °. Since one of the position is occupied by the lone pair the geometry is described as V-shaped or bent shaped. 

Being an ionic compound NaCl gives Cl negative ion and thus gives White ppt. with silver nitrate but CCl₄ is a covalent compound and thus do not give Cl negative ions.

P₁V₁ = P₂V₂ 

200 × 10 = 1 × V₂

V₂ = 2000 L 

Number of Breaths = 2000L/0.5L = 4000

Screening Effect: The electrons of inner shells (i.e. core electrons) screen the outermost electrons from the attractive pull of the nucleus. Such type of effect is called screening effect. As the screening effect increases, the effective nuclear charge decreases. Consequently, the force of attraction by the nucleus for the valence shell electrons decreases and therefore the ionization enthalpy decreases.

Given

CI(g) + e⁻ → CI⁻ (g) is 57.86 × 10⁻¹⁰J

(1 x 10¹⁰ atom)

\(\therefore\) Electron gain enthalpy of chlorine i.e. the amount of energy released when 1 mole (6.023 x 10²³) atoms of chlorine are converted into CI^- ions according to the above equation will be

= \(\frac{57.86\times10^{-10}}{1\times10^{10}}\) x 6.023 x 10²³

= -348.49 x 10³ J mol^-1

= -348.49 kJ mol-1 . 

1 eV/atom = 96.49 kJ mol^-1

Electron gain enthalpy of chlorine = -\(\frac{348.49}{96.49}\)

= -3.61 eV/atom

 Ideal gas equation PV= nRT 

 or n/V = P/RT 

 or m/MV = P/RT (as nm = m/M) 

 or d/M = P/RT 

 or P = dRT/M 

(a) The volume will become 4 times 

(b) The volume will remain same

Dipole-dipole interactions are present in polar molecules like HCl. HCl molecules have a permanent dipole moment because the hydrogen atom has a slight positive charge and the chlorine atom has a slight negative charge. Because of the force of attraction between oppositely charged particles, there is a small dipole-dipole force of attraction between adjacent HCl molecules.

Isochore is the plot between P and T for a definite amount of a gas at a constant volume. From different isochors at different volumes draw a line parallel to Temperature axis represent a constant P and cutting the three isochors at T₁,T₂ and T₃ respectively.Fr om the graph we find T₁,>T₂ >T₃. Since V α T, at constant P. Thus V₁ > V₂ > V₃.

Compounds which have the same structure of carbon chain but differ in position of double or triple bonds or functional group are called position isomers and this phenomenon is called Position isomerism. 

e.g., CH₃-CH₂-CH=CH₂ 

CH₃-CH = CH – CH₃

London forces or dispersion forces are developed.

At high pressure and low temperature.

Because of surface tension, the molecules tend to minimize the surface area and sphere has minimum surface area. 

i. 1:1 

ii. P ∝ T (when V and n are constants) 

∴ If temperature is doubled, pressure also doubles. 

∴ P = 2 atm

iii. \(\frac{V_1}{T_1}\) = \(\frac{V_2}{T_2}\) (when P and n are constants)

∴ \(\frac{1}{298}\) = \(\frac{2.5}{T_2}\)

∴ T₂ = 745 K

 Partial pressure = mole fraction x total pressure. For gas A 

 p_A = x_A x P 

Pascal is SI unit of pressure. It is defined as pressure exerted when 1-newton force is acting per square metre area.

(i) At higher temperature inter particle attraction weakens and more number of mole cules escape to vapour. 

(ii) As interparticle forces are stronger in glycerine.

(iv) O₂, N₂, H₂, He

Ideal gas is gas which follows all the gas laws at all temperature and pressure.

Ideal gas:

• The gases which obey’ ideal gas equation over a complete range of temperature and pressure are called ideal gases.
• For an ideal gas, the ratio of PV/RT = 1. 
• In an ideal gas, there are no interactive forces between the molecules and the molecular volume is negligibly small compared to the volume occupied by the gas. The gas particles are considered as point particles.

Density of gas is directly proportional to molar mass.

Real gases are those which do not follow all the gas laws at all temperature and pressure.

Ideal gas follows gas laws at all P & T 

Real gas donot ― gas laws at all P & T. 

Real gas deviate from ideal behaviour due to force of attraction and because of volume of molecules of gases are not negligible.

Boiling point is temperature at which vapour pressure of liquid becomes equal to atmospheric pressure.

Structural isomerism 

The compounds which exhibit this type of isomerism have the same molecular formula but different structures, as in how they are linked to each other. 

Structural isomerism is further classified into

(i) Chain isomerism

(ii) Position isomerism

(iii) Functional group isomerism

(iv) Metamerism

At low temperatures and high pressure, most of gases deviate from ideal gas behavior.

It states that whenever two or more gases, which do not react chemically, are enclosed in vessel, the total pressure is equal to sum of partial pressure of each gas.

It is according to n+l rule: For 4s, n+l = 4+0=4 & for 3d, n+l = 3+2 = 5, so 4s has lower energy than 3d orbital.

This is because PCC is a mild oxidizing agent and can oxidize methanol to methanal only. While KMnO₄ is strong oxidizing agent which oxidizes it to methanoic acid.

Aromatic acids have higher molecular weight and strong Vander Waals force of attraction as compared to aliphatic acids so they are solids.

(A) The glacier

(B) The meanders

(A) The sand dunes

Sand Dunes: The unstable hills of sand formed due to weathering and persistent wind action are called sand dunes.

Plucking: Lifting pieces of rock and transporting them by glaciers is called plucking.

(i) Complex salts

(ii) Alkali

(a) Gypsum – CaSO₄ .2H₂O

(b) Copper sulphate crystals – CuSO₄ .5H₂O

(c) Sodium carbonate crystals – Na₂CO₃ .10H₂O

(i), (ii)

(i) 20 g of NaOH in 200 mL of solution
(ii) 0.5 mol of KCl in 200 mL of solution

(iii), (iv)

(iii) 28 g of N₂ and 32 g of O₂

(iv) 12 g of C(s) and 23 g of Na(s)

The natural fibers are obtained from plants and animals, whereas the synthetic fibers are obtained by chemical processing of petrochemicals. Unlike natural fibers, manufacturing of synthetic fibers do not require to cut trees or hunting of any animal. In this way manufacturing synthetic fibers is actually helping conservation forests.