List of top Chemistry Questions

Sodium Carbonate cannot be used in place of $(NH_4)_2CO_3$ for the identification of $Ca^{2+},\, Ba^{2+}$ and $Sr^{2+}$ ions (in group V) during mixture analysis because :

The correct set of four quantum numbers for the valence electrons of rubidium atom $(Z = 37)$ is

Benzene and naphthalene form an ideal solution at room temperature. For this process, the true statement(s) is (are)

Equimolar solutions of the following compounds are prepared separately in water. Which will have the lowest pH value ?

In the reaction A is

Some meta-directing substituents in aromatic substitution are given. Which one is most deactivating ?

The order of stability of the following tautomeric compounds is

What is the maximum numbers of electrons that can be associated with the following set of quantum numbers ?
n = 3, l=1 and m = -1

The value of Planck's constant is 6.63 × 10^-34 Js. The speed of light is 3 x 10¹⁷ nm s^-1. Which value is closest to the wavelength in nanometer of a quantum of light with frequency of 6 x 10¹⁵ s^-1?

A reaction having equal energies of activation for forward and reverse reactions has

According to Freundlich adsorption isotherm, the amount of gas adsorbed at very high pressure

Which of the following is not the product of dehydration of

Equal weights of $NaCl$ and $KCl$ are dissolved separately in equal volumes of solutions. Molarity of the two solutions will be :

How many grams of concentrated nitric acid solution should be used to prepare $250\, mL$ of $2 \cdot 0\, M HNO _{3}$ ? The concentrated acid is $70 \% HNO _{3}$.

A compound with molecular mass $180$ is acylated with $CH_3COCl$ to get a compound with molecular mass $390$. The number of amino groups present per molecule of the former compound is

Bond distance in $HF$ is $9.17 \times 10^{-11}\, m$. Dipole moment of $HF$ is $6.10^4 \times 10^{-30}\, Cm$ . The percentage ionic character in $HF$ will be : (electron charge $= 1.60 \times 10^{-19}\, C$)

Which one of the following molecules is polar?

A major component of Borsch reagent is obtained by reacting hydrazine hydrate with which of the following ?

A solution of $(-) 1-chloro-1-$phenylethane in toluene racemises slowly in the presence of a small amount of $SbCl_5$, due to the formation of

The Wurtz-Fittig reaction involves condensation of:

An ether (A), $C_5H_{12}O$, when heated with excess of hot concentrated $HI$ produced two alkyl halides which when treated with $NaOH$ yielded compounds (B) and (C). Oxidation of (B) and (C) gave a propanone and an ethanoic acid respectively. The IUPAC name of the ether (A) is :

Arrange the following compounds in the order of decreasing acidity

Which one of the following is most stable?

In reaction $A + 2B {\rightleftharpoons} 2C + D$, initial concentration of $B$ was $1.5$ times of $[A]$, but at equilibrium the concentrations of $A$ and $B$ became equal. The equilibrium constant for the reaction is :

A gaseous hydrocarbon gives upon combustion $0.72\, g$ of water and $3.08\, g$ of $CO_2$. The empirical formula of the hydrocarbon is