List of top Chemistry Questions asked in WBJEE

Addition of sodium thiosulphate solution to a solution of silver nitrate gives $X$ as white precipitate, insoluble in water but soluble in excess thiosulphate solution to give $Y$. On boiling in water, $Y$ gives $Z . X, Y$ and $Z$ respectively are
Match the flame colours of the alkaline earth metal salts in the Bunsen burner.
In the following compound, the number of ?sp? hybridized carbon is
A piece of wood from an' archaeological sample has $5.0$ counts $\min ^{-1}$ per gram of $C-14$, while a fresh sample of wood has a count of $15.0 \,min ^{-1} \,g ^{-1}$. If half-life of $C-14$ is $5770\, yr$, the age of the archaeological sample is
The protein component of a holoenzyme is known as
$\left(_{32}Ge^{76}, _{34}Se^{76}\right)$ and $\left(_{14}Si^{30}, _{16}S^{32}\right)$ are examples of
The volume of ethyl alcohol (density $1.15\, g/cc$) that has to be added to prepare $100\,cc$ of $0.5\, M$ ethyl alcohol solution in water is
The compressibility factor $(Z)$ of one mole of a van der Waals gas of negligible $�a�$ value is
The order of decreasing ease of abstraction of Hydrogen atoms in the following molecule is
Among the following statements about the molecules $X $ and $Y$, the one (s) which is (are) correct is (are)
The formal potential of $Fe ^{3+} / Fe ^{2+}$ in a sulphuric acid and phosphoric acid mixture $\left(E^{\circ}=+0.61 \,V \right)$ is much lower than the standard potential $\left(E^{\circ}=+0.77 \,V \right) .$ This is due to
The disease that occurs in mature adult human being due to deficiency of calciferol is
The $4^{th}$ higher homologue of ethane is
The structure of $XeF_6$ is experimentally determined to be distorted octahedron. Its structure according to VSEPR theory is
The hydrides of the first elements in groups $15 - 17$, namely $NH_3, H_2O$ and $HF$ respectively show abnormally high values for melting and boiling points. This is due to
To observe an elevation of boiling point of $0.05^?C$, the amount of solute (Mol. $Wt. = 100$) to be added to $100\, g$ of water $(K_b=0.5)$ is
Metal ion responsible for the Minamata disease is
The compound that will have a permanent dipole moment among the following is
Two gases $X$ (Mol. Wt. $M_x$) and $Y$ (Mol. Wt. $M_Y; M_Y > M_x$) are at the same temperature T in two different containers. Their root mean square velocities are $C_X$ and $C_Y$ respectively. If the average kinetic energies per molecule of two gases $X$ and $Y$ are $E_x$ and $E_Y$ respectively, then which of the following relation (s) is (are) true?
The bond angle in $NF _{3}\left(102.3^{\circ}\right)$ is smaller than $NH _{3} (107.2 \left.^{\circ}\right)$. This is because of
The number of amino acids and number of peptide bonds in a linear tetrapeptide (made of different amino acids) are respectively
When phenol is treated with $D_2SO_4/D_2O$, some of the hydrogens get exchanged. The final product in this exchange reaction is
For a spontaneous process, the correct statement(s) is (are)
At $25^{\circ} C$, the molar conductance of $0.007\, M$ hydrofluoric acid is $150$ mho $cm ^{2} \,mol ^{-1}$ and its $\Lambda_{m}^{\circ}=500$ mho $cm ^{2} \,mol ^{-1}$. The value of the dissociation constant of the acid at the given concentration at $25^{\circ} C$ is
The ore chromite is