new chem questions Questions

A blue solution of copper sulphate becomes darker when treated with excess of ammonia. This is because –

The order of stability of complexes of ion Cu+2, Ni+2, Mn+2 and Fe+2 decreases in the order -

Peptide bond group is characteristic of-

Which of the following is not a reducing sugar ?

Gabriel phthalimide reaction is used to prepare -

In hypobromite reaction of amide, carbonyl carbon atom is lost as -

In the reaction sequence : A -> B -> Acetone -> C. A, B and C are -

(CH3)2C = CHCOCH3 can be oxidised to (CH3)2C = CH. COOH by -

CH3 – CH2 – CHO -> Product. The product in the above reaction is:

Which gives a ketone on treating with a Grignard’s reagent -

Indenify A, B, and C in the following reactions–

C2H5NH2 -> B -> C -> D the product D is an-

Zn and Hg do not show variable valency like d-block elements because-

Which of the following statements is correct ?

Compounds (A) and (B) are - [Reference to Reaction Image implied]

Pick out incorrect statement -

A first order reaction takes 69.3 minute for 50% completion. How much time will be needed for 80% completion -

For a reaction 3A -> products, it is found that the rate of reaction doubles, if concentration of A is increased four times, calculate order of reaction -

The charge required to deposit 40.5 g of Al (atomic mass = 27.0 g) from the fused Al2 (SO4)3 is-

The equivalent conductivities at infinite dilution of the cation and the anion of a salt A2B are 140 and 80 ohm–1 cm2 eq–1 respectively. The equivalent conductivity of the salt at infinite dilution is-

0.2 molal acid HX is 20% ionised in solution Kf = 1.86 K molality–1. The freezing point of the solution is -

The molarity of 20% (W/W) solution of sulphuric acid is 2.55 M. The density of the solution is :

The yield of alkyl bromide obtained as a result of heating the dry silver salt of carboxyic acid with bromine what will be the order of formation w.r.t. alkyl bromide -

The best reagent for converting ethanol to chloroethane is -

Which one of the following compounds will be most easily attacked by an electrophile ?

Correct order of nucleophilicity -

The possible number of alkynes with the formula C5H8 is -

The I.U.P.A.C. name of compound (CH3)3C.CH2CONH2 is : –

The formula CnH2n – 2 shows -

Name of the structure of silicates in which three oxygen atoms of [SiO4]4– are shared -

Boron cannot form which one of the following anions ?

The dissociation constant of weak acid HA is 4.9×10–8. After making the necessary approximations . Calculate pH in 0.1 M acid –

For the reaction N2 + 3H2 2NH3 , N2 & H2 were taken in the molar ratio of 1 : 3 . Up to the point of equilibrium 50% each reactant has been reacted. If total pressure at equilibrium is P. The partial pressure of ammonia would be –

The value of KC for the reaction : A + 3B -> 2C is 0.5 at 400°C. Calculate the value of KP

Heat of reaction for C6H12O6 (s) + 6O2 (g) -> 6CO2 (g) + 6H2O (g) at constant pressure is –651 Kcal at 17ºC. Calculate the heat of reaction at constant volume at 17ºC-

A gas absorbs 200J of heat and expands against the external pressure of 1.5 atm from a volume of 0.5 litre to 1.0 litre, Calculate the change in internal energy -

The ratio of sigma to pi bonds in mesitylene is

The electronegativity of O,F,N, Cl and H are 3.5, 4.0, 3.0 and 2.1 respectively. The strongest bond will be :

The correct decreasing order of atomic size among the following species is : Ar, K+, Cl–, S2–, Ca2+

The electronic configuration of an element is 1s2, 2s2 2p6, 3s2 3p4. The atomic number of the element present just below the above element in the periodic table -

The ionization energy of H-atom is 13.6 eV. The ionization energy of Li+2 ion will be -

The ionization energy of He+ is 19.6 × 10–18 J atom–1. The energy of the first stationary state of Li+2 will be -

Naturally occurring chlorine is 75 % Cl35 and 25 % Cl37. Calculate the average atomic mass of chlorine-

8 litre of H2 and 6 litre of Cl2 are allowed to react to maximum possible extent. Find out the final volume of reaction mixture. Suppose P and T remains constant throughout the course of reaction -