List of top Chemistry Questions

Match List - I with List - II.

The total number of amines among the following which can be synthesized by Gabriel synthesis is _________. (A) ethylamine, (B) n-propylamine, (C) benzylamine, (D) aniline

Among the following allotropic forms of sulphur, the number of allotropic forms, which will show paramagnetism is __________

C6H6 freezes at 5.5°C. The temperature at which a solution of 10 g of C4H10 in 200 g of C6H6 freeze is ________ °C. (The molal freezing point depression constant of C6H6 is 5.12°C/m.)

Match List - I and List - II. List - I: (a) Valium, (b) Morphine, (c) Norethindrone, (d) Vitamin B12 List - II: (i) Antifertility drug, (ii) Pernicious anaemia, (iii) Analgesic, (iv) Tranquilizer

The formula of a gaseous hydrocarbon which requires 6 times of its own volume of O2 for complete oxidation and produces 4 times its own volume of CO2 is CxHy. The value of y is _________

In polymer Buna-S : 'S' stands for :

Which one of the following carbonyl compounds cannot be prepared by addition of water on an alkyne in the presence of HgSO₄ and H₂SO₄ ?

The incorrect statement among the following is :

What is the correct order of the following elements with respect to their density ?

The calculated magnetic moments (spin only value) for species $[FeCl_4]^{2-}$, $[Co(C_2O_4)_3]^{3-}$ and $MnO_4^{2-}$ respectively are :

Given below are two statements : Statement I : The value of the parameter “Biochemical Oxygen Demand (BOD)” is important for survival of aquatic life. Statement II : The optimum value of BOD is 6.5 ppm. In the light of the above statements, choose the most appropriate answer from the options given below :

Most suitable salt which can be used for efficient clotting of blood will be :

The correct set from the following in which both pairs are in correct order of melting point is :

Assertion A : Hydrogen is the most abundant element in the Universe, but it is not the most abundant gas in the troposphere. Reason R : Hydrogen is the lightest element.

The correct shape and I-I-I bond angles respectively in $I_3^-$ ion are :

According to Bohr's atomic theory : (A) Kinetic energy of electron is $\propto Z^2 / n^2$. (B) The product of velocity (v) of electron and principal quantum number (n), 'vn' $\propto Z^2$. (C) Frequency of revolution of electron in an orbit is $\propto Z^2 / n^3$. (D) Coulombic force of attraction on the electron is $\propto Z^3 / n^4$. Choose the most appropriate answer :

Considering the reaction of Aniline with $NaNO_2/HCl$ at $0-5^\circ$C to give X, which is then reacted with $H_3PO_2$, identify X and Y :

Considering the reaction of Benzene with CO and HCl in the presence of anhydrous AlCl₃/CuCl (Gattermann-Koch reaction), identify product X :

Considering the hydrolysis of Benzonitrile ($C_6H_5CN$) in acidic medium (H₂O/H⁺), identify the product A :

Reaction of Grignard reagent, C₂H₅MgBr with C₈H₈O followed by hydrolysis gives compound "A" which reacts instantly with Lucas reagent to give compound B, C₁₀H₁₃Cl. The Compound B is :

In order to prepare a buffer solution of pH 5.74, sodium acetate is added to acetic acid. If the concentration of acetic acid in the buffer is 1.0 M, the concentration of sodium acetate in the buffer is __________ M. (Round off to the Nearest Integer). [Given : pKa (acetic acid) = 4.74]

For the reaction 2Fe$^{3+}$(aq) + 2I$^{-}$(aq) → 2Fe$^{2+}$(aq) + I₂(s) the magnitude of the standard molar free energy change, $\Delta_r G^o_m$ = - _________ kJ (Round off to the Nearest Integer). [Given : $E^o_{Fe^{2+}/Fe(s)}$ = -0.440 V; $E^o_{Fe^{3+}/Fe(s)}$ = -0.036 V $E^o_{I₂/2I^{-}}$ = 0.539 V; F = 96500 C]

The total number of unpaired electrons present in the complex K₃[Cr(oxalate)₃] is _________.