List of top Chemistry Questions

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

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

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:

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

The increasing order of metallic character

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

The correct order of melting points of dichlorobenzenes is

Compound $( X )$ undergoes following sequence of reactions to give the Lactone $( Y )$

600 mL of 0.04 M HCl is mixed with 400 mL of 0.02 M H₂SO₄. Find out the pH of resulting solution (Nearest integer).

The magnetic moment of a transition metal compound has been calculated to be 3.87 B.M. The metal ion is

$20 \,mL$ of $01 \,M \,NH _4 OH$ is mixed with $40\, mL$ of $005\, M \,HCl$ The $pH$ of the mixture is nearest to: (Given: $K _{ b }\left( NH _4 OH \right)=1 \times 10^{-5}, \log 2=030$, $\log 3=048, \log 5=069, \log 7=084$, $\log 11=104$ )

During the reaction of permanganate with thiosulphate, the change in oxidation of manganese occurs by value of 3. Identify which of the below medium will favour the reaction

4.5 moles each of hydrogen and iodine is heated in a sealed ten litre vessel. At equilibrium, 3 moles of HI were found. The equilibrium constant for H₂(g) + I₂(g) ⇋ 2HI(g) is _____________ .

1 L, 0.02 M solution of [Co(NH₃)₅SO₄]Br is mixed with 1 L, 0.02 M solution of [Co(NH₃)₅Br]SO₄. The resulting solution is divided into two equal parts (X) and treated with excess of AgNO₃ solution and BaCl₂ solution respectively as shown below:
1 L Solution (X) + AgNO₃ solution (excess) → Y
1 L Solution (X) + BaCl₂ solution (excess) → Z
The number of moles of Y and Z respectively are

Some amount of dichloromethane $\left( CH _2 Cl _2\right)$ is added to $671.141 \,mL$ of chloroform $\left( CHCl _3\right)$ to prepare $2.6 \times 10^{-3} M$ solution of $CH _2 Cl _2$ (DCM) The concentration of DCM is ______$ppm$ (by mass) Given: atomic mass : $C =12$ $H =1$ $Cl =35.5$ density of $CHCl _3=1.49\, g \,cm ^{-3}$

Which one amongst the following are good oxidizing agents?
(A) $ \text{Sm}^{\text{2+}}$
(B) $\text{Ce}^{\text{2+}}$
(C)$ \text{Ce}^{\text{4+}}$
(D) $\text{Tb}^{\text{4+}}$
Choose the most appropriate answer from the options given below:

The separation of two coloured substances was done by paper chromatography The distances travelled by solvent front, substance $A$ and substance $B$ from the base line are $3.25\, cm. 2.08 \, cm$ and $1.05\, cm$ respectively. The ratio of $R_f$ values of $A$ to $B$ is _______

How many bromo products are formed when ethane is reacted with excess of Br₂ on heating?

Match List l with List ll.

List I Coordination Complex	List II Number of unpaired electrons
(I) [Cr(CN)₆]^3-	(a) 0
(II) [Fe(H₂O)₆]²⁺	(b) 3
(III) [Co(NH₃)₆]³⁺	(c) 2
(IV) [Ni(NH₃)₆]²⁺	(d) 4

Choose the correct answer from the options given below:

Which transition in the hydrogen spectrum would have the same wavelength as the Balmer type transition from $n =4$ to $n =2$ of $He ^{+}$spectrum

Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason $R$ :

Assertion (A) : Acetal / Ketal is stable in basic medium.

Reason (R) : The high leaving tendency of alkoxide ion gives the stability to acetal ketal in basic medium

In the light of the above statements, choose the correct answer from the options given below

Which of the following compounds is an example of Freon?