Identify B in the following reaction
Replacement of Cl of chlorobenzene to give phenol requires drastic conditions but chlorine of 2, 4-Dinitrochlorobenzene is readily replaced because
In its reaction with silver nitrate acetylene shows
1-Butyne reacts with cold alkaline KMnO₄ to yield
When a mixture of solid NaCl, solid K₂Cr₂O₇ is heated with conc.H₂SO₄, orange red vapour are obtained. These are of the compound
An ion has 18 electrons in the outermost shell. The ion is
Which of the following sets of quantum numbers is not possible?
The value of the energy for the first excited state of hydrogen will be
The moleucle that deviated from octet rule is
Which pair among the following is isostructural?
Since enthalpy of elements in their natural state is taken to the zero .The value of ∆Hf of compounds
Which one of the following statement is false?
The first order rate constant for the decomposition of N₂O₅ is 6.25 x 10-4 second-1. The half-life for this decomposition is
The state of equilibrium refers to
The equilibrium constant for a reaction is 73 at 298 K. The value of standard free energy change is
Tranquilisers are substances used for the treatment of
The IUPAC name of CH₃CH=CHCOOC₂H₅ is
Which of the following statement about fluorine is not correct?
Industrial production of fluorine entails the electrolysis of hydrogen fluoride in the presence of potassium fluoride. Under these conditions, the potassium fluoride (KF) converts to potassium bifluoride (KHF2), which is the actual electrolyte. This potassium bifluoride aids electrolysis by greatly increasing the electrical conductivity of the solution. Fluorine gas forms at the anode, and hydrogen gas at the cathode.
HF + KF → KHF2
2 KHF2 → 2 KF + H2 + F2
How many EDTA (ethylemediaminetetra acetic acid) molecules are required to make an octahedral complex with Ca2+ ion?
In the reaction A + e⁻ → A⁻
3.2 oxygen is diffused in 10 minutes. In similar conditions, 2.8 g nitrogen will diffuse in
Which of the following statements is false for alkali metals?
20 litres of hyydrogen gas at STP weigh about
The chloride of an element A gives a neutral solution in water. In the periodic table, the element A belongs to
Al is more rective than Fe but Al is less easily corroded than Fe because
Glass is a
C and Si have
Both carbon and silicon have 4 valence electrons and so they have many similar physical properties.
Because they have different number of electrons in the penultimate shell (carbon 2 and silicon 8 electrons), they also show many different chemical properties.
Which of the following is the correct statement for PH₃?
Na₂S₂O₃ is prepared by
The nitride salt of Ca when treated with H₂O gives
Which one of the following order is correct for the bond energies of halogen molecules?
When two ice cubes are pressed over each other, they unite to form one cube. Which of the following forces is responsible to hold them together?
Which of the following salts on dissolution in water gives pH less than 7 at 25oC ?
Which of the following is not a Lewis acid?
Aqueous solution of sodium acetate is
Which of the following isomerism is not found in alkenes?
Which of the following is the correct decreasing order of acidic strength of
1. Methanoic acid
2. Ethanoic acid
3. Propanoic acid
4. Butanoic acid
Two elements A and B are isotonic having atomic no. 32 and 34. If atomic mass of A is 52, the atomic mass of B will be
To impart high energy to sub atomic particles, the particle accelerator used is
An organic compound of molecular formula, C₃H₆O did not give a silver mirror with Tollen's reagent, but gave an oxime with hydroxylamine. It may be
Replacement of Cl of chlorobenzene to give phenol requires drastic conditions but chlorine of 2,4-dinitrochlorobenzene is readily replaced. This is because
NO2 is an electron withdrawing group and it withdraws e - from ortho/para positions. That's why it facilitate nucleophilic substitution reactions.
Benzylamine reacts with nitrous acid to form
Dynamite is prepared by mixing nitroglycerine with
Conc. HNO3 forms NO2+ in presence of :
Which is not the resonance structure of aniline?
Which of the following forms with an excess of CN⁻(cyanide ions) a complex having co-ordination number two
Phenol when heated with concentrated nitric acid gives
Which of the following is a chain growth polymer?
The Beilstein test for organic compounds is used to detect
Which substance is serving as a reducing agent in the following reaction? 14H⁺ + Cr₂O₇2- + 3Ni → 2Cr+3 + 7H₂O + 3Ni2+
Anti-ferromagnetic substances possess
A solution containing As+3, Cd2+, Ni2+ and Zn2+ is made alkaline with dilute NH₄OH and treated with H₂S. The precipitate obtained will consist of :
6 grams of urea is dissolved in 16.2 grams of water at 25oC . What is the vapour pressure (in mm) of the resultant solution? The vapour of water at 25oC is 24 mm
An example of an alkane molecule with least number of carbon atoms which is optically active is:
How much quick lime can be obtained from 25 gm of CaCO₃ ?
Fog is a colloidal solution of
In which of the following compounds transition metal is in oxidation state zero ?
Which one of the following metal ions is colourless
The catalyst used in the manufacture of sulphuric acid by contact process is