Arrange the following compounds in the decreasing order of reactivity towards Sn1 reaction
(A) (Ph)3C-1
(B) (Ph)3C-Br
(C) (Ph)3C-Cl
(D) (Ph)3C-F
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Read the following passage given below and answer the question.
Production of electricity by thermal plants is not very efficient method. It is now possible to make cells in which reactants are fed continuously to the electrodes and products are also removed continuously. One of the most successful fuel cells is hydrogen fuel cell.
In hydrogen fuel cell, the reactants are bubbled through which electrodes?

A compound forms hexagonal closed packed structure. What is the number of tetrahedral voids in \(0.8\text{ mol}\) of it?

The half-life of a first order reaction:
(A) depends on the reactant concentration raised to the first power
(B) depends on rate constant
(C) is independent of the reactant concentration
(D) is independent of rate constant
Choose the correct answer from the options given below :

Read the passage carefully and answer
When a metal is placed in a solution of its ions, the metal can lose electron and can go in the solution as ion or the metal ion in the solution can take electron from the electrode and get deposited as metal. Thus, the electrode acquires either positive or negative charge with respect to the solution leading to the development of a potential difference between the metal electrode and the solution. This potential difference is called the electrode potential of the metal. The electrode potential of a metal is a measure of relative tendency to undergo oxidation (loss of electron) or reduction (gain of electron). When the concentration of the ions in the solution is unity, the electrode potential is called standard electrode potential. The magni of potential depends upon the nature of electrode, concentration of ions in solution and the temperature. In a galvanic cell, the electrode at which oxidation occurs is known as anodic half-cell and the electrode at which reduction occurs is known as cathodic half cell. The emf of the cell in terms of standard reduction potential is given by \(E_{\text {cell }}^{\circ}=E_{\text {cathode }}^{\circ}-E_{\text {anode. }}^{\circ}\).The standard free energy change of the redox reaction taking place in the cell is related to \(E_{\text {cell }}^{\circ}\) by \(\Delta G^{\circ}=-n F E^{\circ}\). A redox reaction would occur spontaneously if the free energy change is negative. The equilibrium constant of the reaction is related to the standard free energy change by \(\Delta G^{\circ}=-R T \ln K\).
The half call reaction is the one that

A brown ring is formed in the ring test for \(NO _3^{-}\)ion. It is due to the formation of:

Question based on the following passage :
P-Block elements are placed in group 13 to 18 in the periodic table. Group 15 is nitrogen family.
Nitrogen can react with hydrogen, oxygen, halogens etc. It shows multiple oxidation states in its various oxides i.e. \(N_2O, N_2O_3, N_2O_5\) etc. Important allotropic forms of phosphorus are white, red and black phosporus. Various compounds of phosphorus are phosphine, \(PCl_3, PCl_5\) and oxoacids of phosphorus. Oxidation states \(+1\) to \(+5\) are seen in various oxoacids of phosphorus. Group 17 elements are collectively known as halogens. Bond dissociation enthalpy of \(F_2\) is smaller than \(Cl_2\).
The gases present in group 18 are chemically unreactive, they form only few compounds. Neil Bartlett (in 1962) observed the reaction of a noble gas. Since then, many noble gas compounds have been synthesised.
The process used for the preparation of Oleum is :

Which of the following contribute to increase in population density?

Read the passage below and answer the question:
The accumulation of molecular species at the surface rather than in the bulk of a solid or liquid is termed as adsorption. There are two types of adsorption. In physisorption, attractive forces are mainly Van der Waals while in chemical adsorption adsorbate is held with chemical bonds adsorbent. Adsorption increases with increase in pressure and decreases as temperature is increased.
Critical temperature of few gases are given SO2 (630К), СН4 (190K), H₂ (33K). What is the correct order of case of physi-adsorption of these gases?

In a plane electromagnetic wave, the magnetic field oscillates sinusoidally at a frequency of\(2.0 \times 10^{10} Hz\) and amplitude \(1.6 \times 10^{-7} T\). The amplitude of the oscillating electric field is:

A proton, an electron, a neutron and an alpha particle have the same energy. Their de Broglie's wavelengths are given below:
(A) \( \lambda_{proton} \)
(B) \( \lambda_{electron} \)
(C) \( \lambda_{neutron} \)
(D) \( \lambda_{alpha} \)
Arrange these wavelengths in decreasing order. Choose the correct answer from the options given below:

Ethanoic acid can be converted into ethanol using reagent

Match List-l with List-II

List-I	List-II
(A) Kolbe's reaction	(I) Preparation of symmetrical and unsymmetrical ethers
(B) Williamson synthesis	(II) Preparation of Salicylic acid
(C) Lucas test	(III) Organo-Magnesium halide
(D) Grignard's reagent	(IV) Distinction between different types of alcohols

Choose the correct answer from the options given below: