Identify the incorrect statement about halogens. qquad F_(2) is the best oxidant & non metal with highest S*R*P value The only halogen that oxidises water is Cl_(2) The halogen that occurs in liquid state at 25^(@)C is Br_(2) . Among all halogens ^(I_(2)) having strong Vander waals forces among its molecules.

Statement-1: All halogens are coloured. Statement-2: Halogens exist in diatomic gaseous state. Statement-3: F_(2) is more reactive than Cl_(2)

Which of the statement is/are true about the reactivity of halogenation of alkanes ? The reactivity ordar is F_(2) gt C1_(2) gt Br_(2) gt I_(2) . I. Lower the activation energy for the chain initiation step, more reactive is the halogen. II. Lower the activation energy for the first chain propagation step, more reactive is the halogen. III. More negative is the overall heat of the reaction (Delta H_(r)^(@)) of halogenation ofg alkane, more reactive is the halogen. IV. Lower the activation energy for the second chain-propagation step, more reactives is the halogen.

(A) Suggest a possible reason for the following observation: (i) In the solid state, PC l_(5) behaves as an ionic species. (ii) H_(2)S is more acidic than water. (iii) Fluorine forms the largest number of inter halogen compounds amongst the halogens.

Three identical capacitors C_(1),C_(2) and C_(3) have a capacitance of 1.0 mu F each and they are uncharged initially. They are connected in a circuit as shown in the figure and C_(1) is then filled completely with a dielectric material of relative permittivity epsilon_(r) . The cell electromotive force (emf) V_(0)=8V . First the switch S_(1) is closed while the switch S_(2) is kept open. When the capacitor C_(3) is fully charged, S_(1) is opened and S_(2) is closed simultaneously. When all the capacitors reach equilibrium, the charge on C_(3) is found to be 5 mu c . The value of epsilon_(r) = ____________.

Nucleophilic substitution reactions generally expressed as Nu^(-) +R-L rarr R-Nu +L^(-) Where Nu^(-) rarr Nucleophile , R-L rarr substrate, L rarr leaving group The best leaving groups are those that become the most stable ions after they depart. since most leaving group leave as a negatibe ion, the best leaving groups are those ions that stabilize a negative charge most effectively. A good leaving group should be (a) electron-withdrawing to polarize the carbon (b) stable once it has left (not a strong base) (c) polaristable to maintain partial bonding with the carbon in the transition state (both S_(N)1 and S_(N)2) . This bonding helps to stabilise the transition state and reduces the activation energy. Among the following which is false statement?

Nucleophilic substitution reactions generally expressed as Nu^(-) +R-L rarr R-Nu +L^(-) Where Nu^(-) rarr Nucleophile , R-L rarr substrate, L rarr leaving group The best leaving groups are those that become the most stable ions after they depart. since most leaving group leave as a negatibe ion, the best leaving groups are those ions that stabilize a negative charge most effectively. A good leaving group should be (a) electron-withdrawing to polarize the carbon (b) stable once it has left (not a strong base) (c) polaristable to maintain partial bonding with the carbon in the transition state (both S_(N)1 and S_(N)2) . This bonding helps to stabilise the transition state and reduces the activation energy. Among the following which is feasible?

It is not possible to measure the atomic radius precisely since the electron cloud surrounding the atom does not have a sharp boundary. One practical approach to estimate the size of an atom of a non-metallic element is to measure the distance between two atoms when they are bound together by a single bond in a covalent molecule and then dividing by two. For metals we define the term "metallic radius" which is taken as half the inter nuclear distance separating the metal cores in the metallic crystal. Then van der waal's radius represents the over all size of the atoms which includes its valence shell in a non bonded situation. It is the half of the distance between two similar atoms in separate molecules in a solid. The atomic radius decreases across a period and increases down the group. Same trends are observed in case of ionic radius. Ionic radius of the species having same number of electrons depends on the number of protons in their nuclei. Sometimes, atomic and ionic radii give unexpected trends due to poor shielding of nuclear charge by d -and f- orbital electrons. Now answer the following three questions: K^(+), CI^(-), Ca^(2+), S^(2-) ions are isoelectronic. The decreasing order of their size is:

The boiling point elevation and freezing point depression of solutions have a number of partical applications. Ethylene glycol (CH_(2)OH-CH_(2)OH) is used in automobile radiatiors as an antifreeze because it lowers the freezing point of the coolant. The same substance also helps to prevent the radiator coolant from boiling away by elevating the boiling point. Ethylene glycol has low vapour pressure. We can also use glycerol as an antifreeze. In order for the boiling point elevation to occur, the solute must be non-volatile, but no such restriction applies to freezing point depression. For example, methanol (CH_(3)OH) , a fairly volatile liquid that boils only at 65^(@)C , is sometimes used as an antifreeze in automobile radiators. Which among the following is the most volatile and the best antifreeze?

When an object moves through a fluid, as when a ball falls through air or a glass sphere falls through water te fluid exerts a viscous foce F on the object this force tends to slow the object for a small sphere of radius r moving is given by stoke's law, F_(w)=6pietarv . in this formula eta in the coefficient of viscosity of the fluid which is the proportionality constant that determines how much tangential force is required to move a fluid layer at a constant speed v, when the layer has an area A and is located a perpendicular distance z from and immobile surface. the magnitude of the force is given by F=etaAv//z . For a viscous fluid to move from location 2 to location 1 along 2 must exceed that at location 1, poiseuilles's law given the volumes flow rate Q that results from such a pressure difference P_(2)-P_(1) . The flow rate of expressed by the formula Q=(piR^(4)(P_(2)-P_(1)))/(8etaL) poiseuille's law remains valid as long as the fluid flow is laminar. For a sfficiently high speed however the flow becomes turbulent flow is laminar as long as the reynolds number is less than approximately 2000. This number is given by the formula R_(e)=(2overline(v)rhoR)/(eta) In which overline(v) is the average speed rho is the density eta is the coefficient of viscosity of the fluid and R is the radius of the pipe. Take the density of water to be rho=1000kg//m^(3) Q. If the sphere in previous question has mass of 1xx10^(-5)kg what is its terminal velocity when falling through water? (eta=1xx10^(-3)Pa-s) A. 1.3m/s B. 3.4m/s C. 5.2m/s D. 6.5m/s

Arrange the halogens F_(2),Cl_(2),Br_(2),I_(2) , in order of their increasing reactivity with alkanes.