List of top Chemistry Questions asked in JEE Main

$50\, mL$ of $0.5\, M$ oxalic acid is needed to neutralize $25\, mL$ of sodium hydroxide solution. The amount of $NaOH$ in $50\, mL$ of the given sodium hydroxide solution is :

A $10\, mg$ effervescent tablet contianing sodium bicarbonate and oxalic acid releases $0.25\, ml$ of ${CO_2}$ at $T$ = $298.15\, K$ and $p = 1$ bar. If molar volume of ${CO_2}$ is $25.0\, L$ under such condition, what is the percentage of sodium bicarbonate in each tablet ? [Molar mass of ${NaHCO_3 = 84 \; g \; mol^{-1}}$]

For a reaction, $N_2(g) + 3H_2(g) \rightarrow 2NH_3(g)$; identify dihydrogen $(H_2)$ as a limiting reagent in the following reaction mixtures.

During compression of a spring the work done is $10\,kJ$ and $2\,kJ$ escaped to the surroundings as heat. The change in internal energy, $\Delta\, U(in\,kJ)$ is:

Enthalpy of sublimation of iodine is $ {24 \; cal \; g^{-1}}$ at $200^{\circ}C$. If specific heat of $I_2(s)$ and $I_2(vap)$ are $0.055$ and $0.031\, cal\, g^{-1}K^{-1}$ respectively, then enthalpy of sublimation of iodine at $250^{\circ}C$ in $cal\, g^{-1}$ is :

For diatomic ideal gas in a closed system, which of the following plots does not correctly describe the relation between various thermodynamic quantities ?

For silver, $ {C_{p}(JK^{-1} mol^{-1}) = 23 + 0.01T}$. If the temperature (T) of $3$ moles of silver is raised from $300\,K$ to $1000\, K$ at $1\, atm$ pressure, the value of $\Delta H$ will be close to

Which one of the following equations does not correctly represent the first law of thermodynamics for the given processes involving an ideal gas ? (Assume non-expansion work is zero)

$5$ moles of an ideal gas at $100\, K$ are allowed to undergo reversible compression till its temperature becomes $200\, K$. If $C_{V} =28 JK^{-1}mol^{-1} , caculate \Delta\, U$ and $\Delta \,pV $ for this process. ($R = 8.0 \, JK^{-1}mol^{-1}$]

Which one of the following statements regarding Henry's law not correct ?

For emission line of atomic hydrogen from $n_i = 8$ to $n_f $ = the plot of wave number $(\bar{v})$ against $( \frac{1}{n^2})$ will be (The Ry dberg constant, $R_H$ is in wave number unit).

Heat treatment of muscular pain involves radiation of wavelength of about $900\, nm$. Which spectral line of H-atom is suitable for this purpose ? $[R_H = 1 \times 10^5 \; cm^{-1}, h = 6.6 \times 10^{-34} \; Js, c = 3 \times 10^8 \; ms^{-1}]$

The size of the iso-electronic species $Cl^-, Ar$ and $ {Ca^{2+}}$ is affected by -

Consider the reversible isothermal expansion of an ideal gas in a closed system at two different temperatures $T_1$ and $T_2 (T_1 < T_2)$. The correct graphical depiction of the dependence of work done $(w)$ on the final volume $(V)$ is:

An open vessel at $27^{\circ}C$ is heated until two fifth of the air (assumed as an ideal gas) in it has escaped from the vessel. Assuming that the volume of the vessel remains constant, the temperature at which the vessel has been heated is :

Points I, II and III in the following plot respectively correspond to ($V_{mp} :$ most probable velocity)

A solution of ${Ni(NO3)2}$ is electrolysed between platinum electrodes using $0.1$ Faraday electricity. How many mole of $Ni$ will be deposited at the cathode?

The isoelectronic set of ions is :

The radius of the largest sphere which fits properly at the centre of the edge of body centred cubic unit cell is : (Edge length is represented by 'a') :

Chlorine on reaction with hot and concentrated sodium hydroxide gives :

For the reaction, ${2A + B \to }$ products, when the concentrations of A and B both where doubled , the rate of the reaction increased from $0.3 \; mol \; L^{-1} s^{-1 }$ to $2.4 \; mol \; L^{-1} s^{-1}$. When the concentration of A alone is doubled, the rate increased from $0.3 \; mol \; L^{-1} s^{-1}$ to $0.6 \; mol \; L^{-1} s^{-1}$ Which one of the following statements is correct ?

Which of the following is a thermosetting polymer?

Ozone is destroyed by CFCs in the upper stratosphere Ozone holes increase the amount of UV radiation reaching the earth.

Aluminium is usually found in $+3$ oxidation stagte. In contarast, thallium exists in $+1$ and $+3$ oxidation states. This is due to :