List of top Chemistry Questions

The first excited state of hydrogen atom is 10.2 eV above its ground state. The temperature needed to excite hydrogen atoms to first excited level, is :

The energy of electron in the nth orbit of hydrogen atom is expressed as $ \sqrt{3}cm $ . The shortest and longest wavelength of Lyman series will be :

In a reversible process, $ \Delta S_{\text{system}}+\Delta S_{\text{surrounding}}$ is

The number of sodium atoms in 2 moles of sodium ferrocyanide is

If the value of $C_{p}$ for nitrogen gas is $j K ^{-1} mol ^{-1}$, then the value of $\Delta H$ on heating $28 \,g$ of nitrogen gas from $0^{\circ} C$ to $100^{\circ} C$ at constant pressure will be :

In a galvanic cell, the electrons flow from :

In a mixture of acetic acid and sodium acetate the ratio of concentrations of the salt to the acid is increased ten times. Then the pH of the solution :

Benzoin is :

A nitrogen containing organic compound gave an oily liquid on heating with bromine and potassium hydroxide solution. On shaking the product with acetic anhydride, an antipyretic drug was obtained. The reactions indicate that the starting compound is :

2-phenyl propene on acidic hydration, gives

The rate of first order reaction is $1.5 \times 10^{-2}$ mol $L^{-1} \, min^{-1}$ at 0.5 M concentration of the reactant. The half-life of the reaction is

The rapid change of $pH$ near the stoichiometric point of an acid base titration is the basis of indicator detection. $pH$ of the solution is related to ratio of the concentrations of the conjugate acid ($HIn$) and base $ (In^-) $ forms of the indicator given by the expression

The Ostwald dilution law is expressed as:

Which of the following is considered to be an anticancer species?

Identify the gas which is readily adsorbed by activated charcoal

In the manufacture of ammonia by the Haber's process, ${N_{2(g)} +3H_{2(g)} <=> 2NH_{3(g)} + 92.3 kJ} $, which of the following conditions is unfavourable ?

The bond order in NO is 2.5 while that in $NO^+$ is 3. Which of the following statements is true for these two species ?

The pair of compounds having metals in their highest oxidation state is

Which one of the following ion has the highest value of ionic radius ?

Aluminium displaces hydrogen from dilute HCl whereas silver does not. The E.M.F. of a cell prepared by combining $Al /Al^{+3}$ and $Ag/Ag^{+}$ is $2.46\, V.$ The reduction potential of silver electrode is $+ 0.80\, V$. The reduction potential of aluminium electrode is :

In the electrolytic method of obtaining aluminium from purified bauxite, cryolite is added to the charge in order to :

When $50\, cm ^{3}$ of $0.2\, N$ $H_{2} SO _{4}$ is mixed with $50 cm ^{3}$ of $1 N\, KOH$, the heat liberated is :

Number of electrons in the valence orbit of nitrogen in an ammonia molecule are

Propene on addition with $ HI, $ gives:

Ethyl chloride is converted into diethyl ether by: