List of top Chemistry Questions asked in KEAM

The effective nuclear charge of an element with three valence electrons is 2.60. What is the atomic number of the element?
Which one of the following statements is false ?
Phenylacetylene on treatment with \(HgSO_4/H_2SO_4, H_2O\) produces
Number of constitutional isomers of alkane with formula $C_6H_{14}$ is
The elution sequence of a mixture of compounds containing chlorobenzene, anthracene and p-cresol developed on an alumina column using a solvent system of progressively increasing polarity is
How many peroxy linkages are present in \(CrO_5\)?
Consider the following compounds
1. \((NH_4)_2Cr_2O_7\) 2. \(NH_4NO_2\) 3. \(NH_4VO_3\) 4. \(NH_4NO_3\)
Which compound(s) yield nitrogen gas upon heating?
More than four bonds are made by how many elements in carbon family?
Select the correct option(s) for the following statements
1. \(Cl_2O\) and \(ClO_2\) are used as bleaching agents
2. \(OCl^-\) salts are used as detergents
3. \(OCl^-\) disproportionates in alkaline medium
4. \(BrO_3^-\) is oxidized in acidic medium
Which of the following combination is correct?
When \(H_2O_2\) is added to an acidified \(K_2Cr_2O_7\) solution
Consider the following statements concerning $N_2H_4$
1. It is an exothermic compound
2. It burns in air with the evolution of heat
3. It has kinetic stability
4. It reduces $Fe^{3+}$ to $Fe^{2+}$ in acidic medium
Which of the following combination is correct?
\(Al_2(SO_4)_3\) is used in the following but not
Portland cement does not contain
When \(SO_2\) gas is passed into aqueous \(Na_2CO_3\) the product(s) formed is(are)
Consider the following species
1. $[O_2]^{2-}$ 2. $[CO]^+$ 3. $[O_2]^+$
Among these sigma bond alone is present in
Maximum number of covalent bonds formed by N and P are
The electronegativities of N, C, Si and P are in the order
Gd(64) has __________ unpaired electrons with sum of spin __________
Which statement(s) is(are) false for the periodic classification of elements?
Which element has the highest first ionization potential?
Two particles A and B of same mass have their total energies $E_A$ and $E_B$ in the ratio $E_A : E_B = 1 : 2$. Their potential energies $U_A$ and $U_B$ are in the ratio $U_A : U_B = 1 : 2$. If $\lambda_A$ and $\lambda_B$ are their de Broglie wavelengths, then $\lambda_A : \lambda_B$ is
The electric field of certain radiation is given by the equation $E=200\{\sin(4\pi\times10^{10}t)+\sin(4\pi\times10^{15}t)\}$ falls on a metal surface having work function 2.0 eV. The maximum kinetic energy (in eV) of the photoelectrons is (use $h=6.63\times10^{-34}\text{Js}$ and $e=1.6\times10^{-19}\text{C}$)
The de Broglie wavelength $\lambda_n$ of the electron in the $n^{\text{th}}$ orbit of hydrogen atom is
Two particles A and B of same mass have their de Broglie wavelengths in the ratio $\lambda_A : \lambda_B = k : 1$. Their potential energies $U_A : U_B = 1 : k^2$. The ratio of their total energies $E_A : E_B$ is
Which of the following compounds are aromatic?