WBJEE 2014 | Chemistry

Which one of the following bond is present in silica?

After equal volumes of 0.10 M solutions of (NH₄)₂ SO₄ and Ba(OH)₂ have been mixed which of the following species is present in greatest concentration in solution?

When the more electro positive metal displace less electropositive metals from their salt solution this process is called

The process of converting hydrated alumina into anhydrous alumina is called :

Which one of the following is the most reactive towards nucleophilic substitution reaction ?

C(s) + O₂  (g) → CO₂ (g)  ΔH=-94 kcal 2CO(s) + O₂  (g) → 2CO (g)  ΔH=-135.2 kcal the heat of formation of CO(g) is :

250 ml of a sodium carbonate solution contains 2.65 g of Na₂ CO₃ . If 10 ml of this solution is diluted to one liter, what is the concentration of the resultant solution (Mol.wt. of Na₂ CO₃ = 106) ?

The de brogile wavelength association with a ball of mass 200 g and moving at a soeed of 5 m/s is of the order of (h = 6.625 × 10^-34 Js)

An ester used as medicine is :

Rancidification is formed by :

Whose name is not associated with the development of periodic table?

Calculate the temperature at which ΔH = 145.6 kJ mol^-1 ,ΔG = -5.2 kJ mol^-1 and ΔS = 216 J k^-1 mol^-1 for a chemical reaction :

Azurite is an ore of :

To become a carbohydrate a compound must contain at least :

A set of compound in which the re-activity of halogen in the ascending order is :

Hannary and Smith relationship is used to calculate :

In group of 15 elements which elements show a fractional oxidation state :

The rates of a gaseous reaction is given by the expression k[A][B] . If the vol of the reaction vessel is suddenly reduced to 1/4 th of the initial volume, the reaction rate relating to original rate will be :

Addition of arsenic to germanium makes the latter:

The standard reduction potential for Fe²⁺ / Fe and Sn²⁺ / Sn electrodes are -0.44 and -0.14 volt respectively . For the cell reaction Fe²⁺ + Sn → F_e + Sn²⁺ , the standard emf is :

The even numbered alkanes have much higher melting point than the next lower n-alkane with odd no of carbon atom. This is due to :

Which of the following will have least hundred rotation about carbon-carbon bond?≡

The cl-cl-cl angle in 1,1,2,2 tetrachloro ethene and tetrachloro methene respectively are :

When sodium dryoxide react with sand, it forms :

Mechanical work is specially important in the system that contain :

A sample of 4.12 mg of unknown alcohol is added to CH₃ MgBr then 1.56 mL of methane at STP was liberated. The alcohol is :

The reagent NH₄Cl and aqueous NH₃ will precipitate :

Zwitter is formed by :

A chemical reaction was carried out at 300 K and 280 K. The rate constants were found to be k₁ and k₂ respectively. Then

When ice melts into water entropy :

Ice floats on water because :

Which of the element is used for detecting obstruction in the digestive system ?

One gram atom of graphite and one gram atom of diamond were separately burnt to carbon dioxide. The amount of heat liberated were 393.5 kJ and 395.4 kJ respectively. It follows that :

Sodium Carbonate is manufactured by :

3.92 g of ferrous ammonium sulphate crystals are dissolved in 100 ml of water , 20 ml of this solution requires 18 ml of KMnO₄ during titrating of complete oxidation. The weight of KMnO₄ present in one liter solution is :

The proper rays for radiocarbon dating are :

For which of the following species Bohr's theory is not applicable ?

Diborane on reaction with olefins forms :

Which of the following oxide is known as nitronium nitrate ?

The flocculation value is expressed in terms of :

Which isomeric form of benzene hexachloride is used as insecticide :

Which of the following is used in Holme's signals for ships?

Which of the following species are isoelectronic ? (I) CH ₃ ⁺ (II) H₃ O (III) NH₃ (IV) CH₃ ^-

KMnO4 oxidizes oxalic acid in acidic medium. The no of CO₂ molecules produced as per the balanced equation is :

Magic no s are?

Which of the following is least stable?

Which of the following set of quantum no is not applicable for an electron in an atom ?

Solution of 0.1 N NH₄ OH and 0.1 NH₄ Cl has pH 9.25 . Then pK_b of NH₄ OH is :

Acetamide is :

Which of the following oxide is known as nitronium nitrate?