List of top Chemistry Questions asked in KEAM

For two isomorphous crystals A and B, the ratio of density of A to that of B is 1.6 while the ratio of the edge length of B to that of A is 2. If the molar mass of crystal B is 200 g mol$^{-1}$, then molar mass of crystal A is}

Which of the following changes in the respective bond order values are caused by removal of an electron from N$_2$ and F$_2$ molecules?

Aluminium (Atomic mass = 27) crystallizes in a cubic system with edge length of 4 \AA. Its density is 2.7 g cm$^{-3}$. The number of aluminium atoms present per unit cell is}

An odd electron molecule among the following is

The number of electrons with azimuthal quantum number \(l = 1\) and \(l = 2\) for Cr in ground state are respectively

The minimum values of uncertainties involved in the determination of both the position and velocity of a particle are respectively \(1\times10^{-10}\,m\) and \(1\times10^{-10}\,ms^{-1}\). Then, the mass (in kg) of the particle is

The threshold frequency of a metal corresponds to the wavelength of \(x\) nm. In two separate experiments ‘A’ and ‘B’, incident radiations of wavelengths \(\frac{x}{2}\) nm and \(\frac{x}{4}\) nm respectively are used. The ratio of kinetic energy of the released electrons in experiment ‘B’ to that in experiment ‘A’ is

Acid catalysed hydration of alkene is an example for

How does the electron gain enthalpies vary across a period and down a group?

n-hexane on heating to $773 \,K$ at $10-20$ atmospheric pressure in the presence of oxides of vanadium supported over alumina, yields

Which one of the following monomers form biodegradable polymer?

Which one of the following is an allylic halide ?

Which one of the following compounds shows cis-trans isomerism?

The equilibrium constant for the equilibrium $PCl _{5}(g) \rightleftharpoons PCl _{3}(g)+ Cl _{2}(g)$ at a particular temperature is $2 \times 10^{-2}\, mol L ^{-1}$. The number of moles of $PCl _{5}$ that must be taken in a one litre flask at the same temperature to obtain a concentration of $0.20$ mole of chlorine at equilibrium is

Which one of the following is not an isomer of $3-methylbut-1-yne$?

The total number of optical isomers possible for 2,3-dibromobutane is

In which one of the following the central atom is sp\textsuperscript{3 hybridized?}

The salt of an alkali metal gives violet colour in the flame test. Its aqueous solution gives a white precipitate with barium chloride in hydrochloric acid medium. The salt is

Which of the following are isoelectronic species?
(i) NH\textsubscript{3 (ii) CH\textsubscript{3}\textsuperscript{+} (iii) NH\textsubscript{2}\textsuperscript{--} (iv) NH\textsubscript{4}\textsuperscript{+}
Choose the correct answer from the codes given below}

The reaction of H\textsubscript{2 is given below
H\textsubscript{2} + CO + R--CH=CH\textsubscript{2} \(\rightarrow\) R--CH\textsubscript{2}--CH\textsubscript{2}--CHO
is specifically called as}

At 273 K, the density of a certain gaseous oxide at 2 atmosphere is same as that of dioxygen at 5 atmosphere. The molecular mass of the oxide (in g mol\textsuperscript{--1}) is

If two moles of an ideal gas at 500 K occupies a volume of 41 litres, the pressure of the gas is (R = 0.082 L atm K\textsuperscript{--1} mol\textsuperscript{--1})

Potassium dichromate belongs to which crystal system?

Molecular formulae and shapes of some molecules are given below. Choose the incorrect match

Arrange the following species in the correct order of their stability:
$C_2$, $Li_2$, $O_2^+$, $He_2^+$