List of top Questions asked in JEE Main- 2019

The transition element that has lowest enthalpy of atomisation, is :

The correct order of the first ionization enthalpies is:

The correct order of the spin-only magnetic moment of metal ions in the following low spin complexes, ${[V(CN)_6]^{4-}, [Fe(CN)6]^{4-}, [Ru (NH3)6]^{3+},}$ and ${[Cr(NH3)6]^{2+}}$, is :

The statement that is INCORRECT about the interstitial compounds is :

Among the following compounds most basic amino acid is :

What is the IUPAC name of the following compound ?

Consider the following reversible chemical reactions : ${A_2(g) + Br_2 (g) <=>[K_1] 2AB(g) }$ ....(1) ${ 6AB(g) <=>[K_2] 3A_2 (g) + 3B_2(g) }$ ...(2) The relation between $K_1$ and $K_2$ is :

Which amongst the following is the strongest acid ?

$5$ moles of $AB_2$ weigh $125 \times 10^{-3}\; kg$ and $10$ moles of $A_2B_2$ weigh $300 \times 10^{-3} \; kg$. The molar mass of $A(M_A)$ and molar mass of $B(M_B) $ in $kg\, mol^{-1}$ are :

$50\, mL$ 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 :

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.

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

$5$ 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 -

If surface tension (S), Moment of inertia (I) and Planck's constant (h), were to be taken as the fundamental units, the dimensional formula for linear momentum would be : -

A person standing on an open ground hears the sound of a jet aeroplane, coming from north at an angle $60^\circ$ with ground level. But he finds the aeroplane right vertically above his position. If $\upsilon$ is the speed of sound, speed of the plane is :

In a car race on straight road, car $A$ takes a time $t$ less than car $B$ at the finish and passes finishing point with a speed $'v'$ more than that of car $B$. Both the cars start from rest and travel with constant acceleration $a_1$ and $a_2$ respectively. Then $'v'$ is equal to :

In the cube of side $'a'$ shown in the figure, the vector from the central point of the face $ABOD$ to the central point of the face $BEFO$ will be:

Two vectors $\vec{A}$ and $\vec{B}$ have equal magnitudes. The magnitude of $(\vec{A} + \vec{B})$ is 'n' times the magnitude of $(\vec{A} - \vec{B})$ . The angle between $\vec{A}$ and $\vec{B}$ is :

In a hydrogen like atom, when an electron jumps from the $M$ - shell to the $L$ - shell, the wavelength of emitted radiation is $\lambda$. If an electron jumps from $N$-shell to the $L$-shell, the wavelength of emitted radiation will be :