List of top Chemistry Questions asked in JEE Main

The energy of an electron in the first Bohr orbit of hydrogen atom is $-2.18×10^{-18}J$. Its energy in the third Bohr orbit is ____.

A litre of buffer solution contains $01$ mole of each of $NH _3$ and $NH _4 CL$ On the addition of $002$ mole of $HCl$ by dissolving gaseous $HCl$, the $pH$ of the solution is found to be ____ $\times 10^{-3}$ (Nearest integer) [Given : $pK _5\left( NH _3\right)=4745$ $ \log 2=0301$ $\log 3=0477$ $T =298 K ]$

The effect of addition of helium gas to the following reaction in equilibrium state, is : $PCl _5( g ) \rightleftharpoons PCl _3( g )+ Cl _2( g )$

From the figure of column chromatography given below, identify incorrect statements

A. Compound 'c' is more polar than 'a' and 'b'
B. Compound 'a' is least polar
C. Compound 'b' comes out of the column before 'c' and after 'a'
D. Compound 'a' spends more time in the column
Choose the correct answer from the options given below

The standard reduction potential at 298 K for the following half cells are given below
NO − 3 3 − + 4H+ + 3e- → NO(g) +2H2O E0 = 0.97V
$V^{2+} (aq) + 2e^-→V$ E⁰ = -1.19V
$Fe^{3+}(aq) + 3e^- → Fe$ E⁰= -0.04V
$Ag^+ (aq) + e^- → Ag(s)$ E⁰ = 0.80V
$Au^{3+}(aq)+3e^-→Au(s)$ E⁰= 1.40V
The number of metal(s) which will be oxidized by $N0^-_3$ Oin aqueous solution is______.

Compound A from the following reaction sequence is

Br2 , C S 2 0 − 5 ° C 0 − 5 ° 𝐶 → 𝐵 𝑟 2 , 𝐶 𝑆 2 B. N a N O 2 / H C l

Match List I with List II

Choose the correct answer from the options given below:

Major product of the following reaction is

Match the terms in Column-I with their description in Column-II and choose the correct option:

Column I (Chemical reactions)		Column II (Enzymes used)
(i)	Glucose → CO₂+ Ethanol	a	Pepsin
(ii)	Sucrose→Glucose + Fructose	b	Diastase
(iii)	Starch →Maltose	c	Zymase
(iv)	Protein→Amino acids	d	Invertase

The increasing order of metallic character

The wave function $(\Psi)$ of $2 s$ is given by $\Psi_{2 n }=\frac{1}{2 \sqrt{2 \pi}}\left(\frac{1}{a_0}\right)^{1 / 2}\left(2-\frac{r}{a_0}\right) e^{-\frac{r}{2 a_0}}$ At $r=r_0$, radial node is formed Thus, $r_0$ in terms of $a_0$

Given below are two statements: one is labeled as Assertion (A) and the other is labeled as Reason (R).
Statement-1: According to Bohr’s Model, angular momentum is Quantized for stationary orbits.
Statement-2: Bohr’s Model doesn’t follow Heisenberg’s Uncertainty Principle.
In the light of the above statements, write the detailed answer:

The number of species from the following carrying a single lone pair on central atom Xenon is ______ .
XeF₅⁺, XeO₃, XeO₂F₂, XeF₅^-, XeO₃F₂, XeOF₄, XeF₄

The correct relationships between unit cell edge length ‘a’ and radius of sphere ‘r’ for face-centred and body-centred cubic structures respectively are:

How many of the transformations given below would result in aromatic amines?

It is observed that characteristic $X$-ray spectra of elements show regularity When frequency to the power " $n$ " ie $v^n$ of $X$-rays emitted is plotted against atomic number " $Z$ ", following graph is obtained

Given below are two statements:
Statement I : Pure Aniline and other arylamines are usually colourless.
Statement II : Arylamines get coloured on storage due to atmospheric reduction.
Choose the correct answer

Number of compounds giving (i) red colouration with ceric ammonium nitrate and also (ii) positive iodoform test from the following is_____