Explore topic-wise InterviewSolutions in .

(i) Cr ²⁺ is reducing as its configuration changes from d⁴ to d³ , the latter having a half filled t_2g configuration. On the other hand, the change from Mn ³⁺ to Mn ²⁺ results in the half-filled d⁵ configuration which has extra stability therefore Mn ³⁺ is oxidising.

(ii) Because the high hydration enthalpy of Cu ²⁺ easily compensates the second ionization enthalpy of Cu.

(iii) This is because manganese has electronic configuration [Ar]3d⁵4s², with five unpaired electrons in 3d orbitals.

(i) Antacids: Chemical substances which removes the excess acid in the stomach & raise the pH to appropriate level, e.g., sodium hydrogen carbonate, a mixture of aluminium and magnesium hydroxide, ranitidine, etc.

(ii) Non-ionic Detergents: Non-ionic detergents do not contain any ion in their constitution. One such detergent is formed when stearic acid reacts with polyethylene glycol.

(iii) Antiseptics: These are the chemical substances which prevent the growth of micro organisms and may even kill them but are not harmful to living tissues. Antiseptics are applied to living tissues such as wounds, cuts, ulcers. Dettol, soframicine are antiseptics

(i) Electrophoresis takes place in which colloidal particles move towards the oppositely charged electrode where they lose their charge and get coagulated.
(ii) The path of light becomes visible due to scattering of light by colloidal particles (Tyndall effect).
(iii) The positively charged colloidal particles of Fe(OH)₃ get coagulated by the negatively charged ions provided by electrolyte.

(i) Dipole moment is a product of charge and distance. Since chlorobenzene has lower magnitude of negative charge on Cl atom and shorter C—Cl bond than cyclohexyl chloride due to resonance therefore chlorobenzene has lower dipole moment than cyclohexyl chloride.

(ii) This is because the new intermolecular attractions between haloalkenes and organic solvent molecules have almost the same strength ones being broken in the separate haloalkan and solvent molecules.

In chlorobenzene, phenyl group is electron withdrawing and secondly due to resonance electron pair of chlorine get shifted towards benzene ring but cyclobenzyl group is neither electron withdrawing nor there is resonance hence cyclohexyl chloride has more dipole moment.

(a) Liquid

(b) Solid

(c) Gas

(a) Optimum conditions for the industrial manufacture of ammonia by Haber’s process.
Pressure: 200 bar
Temperature: 723–773 K

Catalyst: Finely divided iron and molybdenum as promoter.

(b) (i) In vapour state sulphur partly exists as S₂ molecule which has two unpaired electrons in the antibonding π* molecular orbitals like O₂ and, hence exhibits paramagnetic behaviour

(ii) White phosphorus is more reactive than red phosphorus due to its discrete tetrahedral structure and angular strain. Red phosphorus is less reactive due its polymeric structure.

In H₂O Bond dissociation enthalpy of O–H is more than S – H bond of H₂S therefore H₂S is better reducing agent than H₂O.

XeF₆ + NaF Na⁺ XeF7]^-

Substances that retain their ferromagnetic property for a long period of time at room temperature are called permanent magnets.

Examples : Steel, alnico, cobalt and ticonal.

(i) Heat waves: As heat waves are transverse or electromagnetic in nature.

Spherical shape with point charges q > 0 or q < 0 at the centre.

When length of a given wire is made n-times by strecting it, its resistance becomes n² times

i.e., R' =n²R = (2)² x 15 = 60Ω 

Resistance of each half part 60/2 = 30Ω

When both parts are connected in parallel, final resistance = 30/2 = 15Ω

Current drawn from battery,

I = V/R

= 3.0/15 = 0.2A

(i) Transducer: A device which convert one form of energy into the other. 

(ii) Repeater: A repeater picks up the signal from the transmitter, amplifies and retransmits it to the receiver sometimes with a change in a carrier frequency.

Forests 

Range of different life forms plays an important role in maintaining ecological balance as they all depend on each other for their survival

(d)  None of these

Outstanding subscription is Assets.

Debentures are generally freely transferable by the debenture holder.

Unrecorded liabilities when paid are shown in debit of realisation account. 

Paid-up Capital is the registered capital of the company.

Allotment of share Account is Personal A/C.

Share allotment account is Personal A/C.

Balance sheet prepared after new partnership agreement assets and liabilities are recorded at Revaluation A/C.

Interest on partner’s capital is calculated on Capital in the beginning.

The balance of Revaluation Account is transferred to old partner’s Capital Accounts in their Old Profit Sharing Ratio.

The following reactions are involved when Cr²⁺ and Fe²⁺ act as reducing agents.

Cr²⁺ ----> Cr³⁺ Fe²⁺ -----> Fe³⁺  

The E⁰ _{Cr³⁺/Cr²⁺} value is - 0.41 V and E⁰_{Fe³⁺/Fe²⁺} is +0.77 V. This means that Cr²⁺ can be easily oxidized to Cr³⁺, but Fe²⁺ does not get oxidized to Fe³⁺ easily. Therefore, Cr²⁺ is a better reducing agent that Fe³⁺.

(1) PCl₅ 

With phosphorus pentachloride (PCl₅) or thionyl chloride (SOCl₂), benzoic acid reacts to form benzoyl chloride (C₆H₅COCl), which is classified as an acid (or acyl) halide.

(2) mixture of conc. HNO₃ and H₂SO₄

Benzoic acid reacts with concentrated nitric acid (HNO₃), in the presence of sulfuric acid as catalyst, leading to nitration of the ring.

Reaction of benzoic acid with fuming sulfuric acid (H₂SO₄) leads to sulfonation of the aromatic ring, in which the functional group SO₃H replaces a hydrogen atom on the aromatic ring.

Antiseptics and disinfectants are effective against micro-organisms. However, antiseptics are applied to the living tissues such as wounds, cuts, ulcers, and diseased skin surfaces, while disinfectants are applied to inanimate objects such as floors, drainage system, instruments, etc. Disinfectants are harmful to the living tissues. Iodine is an example of a strong antiseptic. Tincture of iodine (2 − 3 percent of solution of iodine in alcohol − water mixture) is applied to wounds. 1 percent solution of phenol is used as a disinfectant.

When propionic acid is treated with thionly chloride then propionyl chloride is formed.

CH₃CH₂COOH + SOCl₂ ----> CH₃CH₂COCl + SO₂ + HCl

HF can form the salt KHF₂ while HCL does not form KHCL₂ because KF forms H-bond with HF while KCl cannot form H-bond with HCl.

Glass etching is the techniques of creating art on the surface of glass by applying acidic, caustic, or abrasive substances.

In an inelastic collision the physical quantuty that is conserved is Momentum.

(b) Sublimation, dissolving in water, filtration and evaporation

Oxidation the odd process amongst.

The process used to obtain salt from sea water is Evaporation.

The process of conversion of a solid substance directly into vapours is called Sublimation.

Air  is a mixture.

The various constituents of a mixture can be separated by Simple physical methods.

The process by which common salt is separated from its solution in water is Evaporation.

Camphor  is volatile substance.

(d) All the above are correct

When a mixture of iron fillings and sulphur is added to a test tube containing CS2,

(d) (iv)

(a) It is not transparent and is not stable