List of top Chemistry Questions

The compound X can be separated from spent-lye in soap industry by using distillation under reduced pressure. What is X?

The relative lowering of vapour pressure of an aqueous solution containing a non-volatile solute is 0.0125. The molality of the solution is

What is the product Y in the given reaction sequence?

An element with molar mass \(M\,kg\,mol^{-1}\) forms a face centred cubic unit cell with edge length 405 pm. If the density is \(2.7\times10^{3}\,kg\,m^{-3}\). What is its molar mass \(M\)? \((N_A=6.0\times10^{23}\,mol^{-1})\)

Which of the following reagent(s) will convert n-propyl bromide to alkane with same number of carbon atoms? \[ \text{I. } Zn/H^+ \] \[ \text{II. } Na/\text{dry ether} \] \[ \text{III. } (i)\;alc.KOH \quad (ii)\;H_2/Pt \]

Identify the compound which has \(1^\circ\), \(2^\circ\), \(3^\circ\) and \(4^\circ\) carbons.

Identify the correct statements from the following: I. Group 15 elements form electron rich hydrides II. Density of heavy water is higher than that of water III. Water containing soluble salts of magnesium and calcium is called soft water

The allotrope of carbon with aromatic character is:

Observe the following sequence of reactions and identify the correct statements about \(W\), \(X\) and \(Z\): \[ Ca + O_2 \rightarrow X \xrightarrow{H_2O} Y \xrightarrow{CO_2} Z \xrightarrow{-H_2O} Z \xrightarrow{H_2O/\text{ excess }CO_2} W \] I. W is soluble in water II. Z is used as mild abrasive in toothpaste III. X is slaked lime

Match the following:

Given below are two statements: Statement-I: Solubility of alkaline earth metal hydroxides in water increases down the group. Statement-II: Solubility of alkaline earth metal sulphates in water increases down the group.

Identify the reactions which give orthoboric acid from the following: \[ \text{I. Acidification of an aqueous solution of borax} \] \[ \text{II. Hydrolysis of diborane} \] \[ \text{III. Hydrolysis of boron trichloride} \]

Identify the correct orders for the given properties. I. C-H<C-O<N-O<C-C (Bond length) {II. } H_2S<O_3<NO_2<CO_2 (Bond angle) {III. } He_2^+<B_2<C_2<N_2 (Bond order)

2.9 g of a gas (molar mass \(40\,g\,mol^{-1}\)) at \(T(K)\) occupied the same volume as 0.184 g of dihydrogen at \(17^\circ C\) at the same pressure. The value of \(T(K)\) is:

Match the following.

The solubility of \(BaCO_3\) (molar mass \(197\,g\,mol^{-1}\)) is \(1.4\times10^{-3}\) g per 100 mL. The solubility product constant of \(BaCO_3\) is \(x\times10^{-9}\,mol^2L^{-2}\). The value of \(x\) (nearest integer) is:

Which of the following statement is correct about the balanced equation given below? \[ Cr_2O_7^{2-}(aq)+14H^+(aq)+3S^{2-}(aq) \rightarrow 2Cr^{3+}(aq)+3S(s)+7H_2O(l) \]

Consider the following species: \[ Li_2,\; B_2,\; Be_2,\; C_2,\; O_2,\; O_2^{2-},\; F_2 \] The number of species with bond order value 1 is:

In which of the following reactions \(\Delta S\) (entropy change) is positive?

Identify the pairs in which electron gain enthalpy of the first element is more than that of the second element. \[ \text{I. } F,\ Br \] \[ \text{II. } Na,\ Li \] \[ \text{III. } S,\ O \]

The ratio of wavenumber of first line of Balmer series and wavenumber of second line of Lyman series of hydrogen atom is:

The wavelength of electron in the orbit X of hydrogen atom is \(6\pi a_0\). What is the value of X? (\(a_0=\) radius of first orbit of hydrogen atom)

What is the oxidation state of Phosphorus in \(H_3PO_4\)?

Explain the mechanism of alkaline hydrolysis of bromomethane.