List of top Chemistry Questions asked in AIEEE

Copper crystallises in a face centred cubic lattice with a unit cell length of $361\, pm$. What is the radius of copper atom in $pm$ ?

Consider the following reaction: $C_2H_5OH + H_2SO_4 \to$ Product Among the following, which one cannot be formed as a product under any conditions?

Boron cannot form which one of the following anions?

A gas absorbs a photon of $355 nm$ and emits at two wavelengths. If one of the emissions is at $680 nm$, the other is at:

The value of enthalpy change ($\Delta$H) for the reaction $C_{2}H_{5}OH_{\left(I\right)} + 3O_{2\left(g\right)} \to 2CO_{2\left(g\right)} + 3H_{2}O_{\left(I\right)}$ at $27^{\circ}C$ is $-1366.5 \,kJ \,mol^{-1}.$ The value of internal energy change for the above reaction at this temperature will be :

The correct order of electron gain enthalpy with negative sign of F, Cl, Br and I, having atomic number 9, 17, 35 and 53 respectively, is:

When r, P and M represent rate of diffusion, pressure and molecular mass, respectively, then the ratio of the rates of diffusion $(r_A/r_B)$ of two gases A and B, is given as:

The molecular velocity of any gas is:

A 5.2 molal aqueous solution of methyl alcohol, $CH _{3} OH$ is supplied. What is the mole fraction of methyl alcohol in the solution?

Consider thiol anion $(RS^?)$ and alkoxy anion $(RO^?)$. Which of the following statements is correct ?

The correct sequence which shows decreasing order of the ionic radii of the elements is

Ionisation energy of $He^+$ is $19.6 \times 10^{-18}\, J\, atom^{-1}$. The energy of the first stationary state $(n = 1)$ of $Li^{2+}$ is

On mixing, heptane and octane form an ideal solution. At $373\, K$, the vapour pressures of the two liquid components (heptane and octane) are $105 \,kPa$ and $45\, kPa$ respectively. Vapour pressure of the solution obtained by mixing $25.0\,g$ of heptane and $35\, g$ of octane will be (molar mass of heptane $= 100\, g \,mol^{-1}$ and of octane $= 114\, g \,mol^{-1}$).

If sodium sulphate is considered to be completely dissociated into cations and anions in aqueous solution, the change in freezing point of water $\left(\Delta T_{f}\right)$, when $0.01\, mol$ of sodium sulphate is dissolved in $1\, kg$ of water, is $(K_f = 1.86\, K\, kg\, mol^{-1})$

The time for half life period of a certain reaction $A \to $ products is $1$ hour. When the initial concentration of the reactant $?A?$, is $2.0\, mol\, L^{-1}$, how much time does it take for its concentration to come from $0.50$ to $0.25\, mol\, L^{-1}$ if it is a zero order reaction ?

Consider the reaction : $Cl_{2(aq)} + H_2S_{(aq)} \to S_{(s)} + 2H^+_{(aq)} + 2Cl^-_{(aq)}$ The rate equation for this reaction is rate $= k [Cl_2] [H_2S]$ Which of these mechanisms is/are consistent with this rate equation ? $\left(A\right) Cl_{2} + H_{2}S \to H^{+} + Cl^{-} + Cl^{+} + HS^{-} $ (slow) $Cl^{+} + HS^{-} \to H^{+} + Cl^{-} + S $ (fast) $\left(B\right) H_{2}S \rightleftharpoons H^{+} + HS^{-}$ (fast equilibrium) $Cl_{2} + HS^{-} \to 2Cl^{-} + H^{+} + S$ (slow)

$29.5\, mg$ of an organic compound containing nitrogen was digested according to Kjeldahl?s method and the evolved ammonia was absorbed in $20\, mL$ of $0.1\, M\, HCl$ solution. The excess of the acid required $15 \,mL$ of $0.1\, M\, NaOH$ solution for complete neutralization. The percentage of nitrogen in the compound is

In aqueous solution the ionization constants for carbonic acid are $K_1 = 4.2 \times 10^{-7}$ and $K_2 = 4.8 \times 10^{-11}$ Select the correct statement for a saturated 0.034 M solution of the carbonic acid.

At $25^{\circ}C$, the solubility product of $Mg\left(OH\right)_{2} $ is $1.0 \times 10^{-11}$. At which pH, will $Mg^{2+}$ ions start precipitating in the form of $Mg\left(OH\right)_{2}$ from a solution of $0.001 \,M \,Mg^{2+}$ ions ?

The standard enthalpy of formation of $NH_3$ is $-46.0\, kJ \,mol^{-1}$. If the enthalpy of formation of $H_2$ from its atoms is $-436\, kJ \,mol^{-1}$ and that of $N_2$ is $-712\, kJ\, mol^{-1}$, the average bond enthalpy of $N-H$ bond in $NH_3$ is

The Gibbs' energy for the decomposition of $ {Al2O3 }$ at $500^{\circ} C$ is as follows: $ { \frac{2}{3} Al_2 O_3 -> \frac{4}{3} Al + O_2 ; \Delta_r G = + 960 \, kJ \, mol^{-1} }$ The potential difference needed for the electrolytic reduction of aluminium oxide $ {(Al2O3)}$ at $500^{\circ} C$ is at least

Solubility product of silver bromide is $5.0 \times 10^{-13}$. The quantity of potassium bromide (molar mass taken as 120 g of $mol^{-1}$) to be added to 1 litre of 0.05 M solution of silver nitrate to start the precipitation of AgBr is

Percentage of free space in cubic close packed structure and in body centred packed structure are respectively

For a particular reversible reaction at temperature $T, \,\Delta H$ and $\Delta S$ were found to be both $+ve$. If $T_{e}$ is the temperature at equilibrium, the reaction would be spontaneous when

Biuret test is not given by