List of top Chemistry Questions

A sample of a metal oxide has formula $M _{0.83} O _{1.00}$ The metal $M$ can exist in two oxidation states $+2$ and $+3$ In the sample of $M _{0.83} O _{1.00}$, the percentage of metal ions existing in $+2$ oxidation state is___$ \%$ (nearest integer)

When 2 litre of ideal gas expands isothermally into vacuum to a total volume of 6 litre, the change in internal energy is______J (Nearest integer)

A solution containing 2 g of a non-volatile solute in 20 g of water boils at 373.52 K. The molecular mass of the solute is ------- g mol$^{-1}$ (Nearest integer).
Given: Water boils at 373 K, $K_b$ for water = 0.52 K kg mol$^{-1}$.

Amongst the following, the number of species having the linear shape is $XeF _2, I _3^{+}, C _3 O _2, I _3^{-}, CO _2, SO _2, BeCl _2 \text { and } BCl _2^{\ominus}$

Given below are two statements:
Statement I : H₂O₂ is used in the synthesis of Cephalosporin
Statement II : H₂O₂ is used for the restoration of aerobic conditions to sewage wastes.
In the light of the above statements, choose the most appropriate answer from the options given below :

Boric acid is solid, whereas $BF _3$ is gas at room temperature because of

Match List -I with List-II

LIST-I (Atomic number)	LIST-II (Block of periodic table)
(A) 37 (K)	I. p-block
(B) 78 (Pt)	II. d-block
(C) 52 (Te)	III. f-block
(D) 65 (Tb)	IV. s-block

Choose the correct answer from the options given below:

Formation of photochemical smog involves the following reaction in which $A , B$ and $C$ are respectively i $NO _2 \xrightarrow{ h\nu } A + B$ ii $B + O _2 \rightarrow C$ iii $A + C \rightarrow NO _2+ O _2$ Choose the correct answer from the options given below:

The element playing significant role in neuromuscular function and interneuronal transmission is :

Which of the following compounds would give the following set of qualitative analysis?

Fehling's Test: Positive
Na fusion extract upon treatment with sodium nitroprusside gives a blood-red colour but not prussian blue

Which of the following is correct order of ligand field strength?

Which one of the following statements is incorrect?

For $OF _2$ molecule consider the following : A Number of lone pairs on oxygen is 2 B FOF angle is less than $1045^{\circ}$ C Oxidation state of $O$ is $-2$ D Molecule is bent ' $V$ ' shaped E Molecular geometry is linear correct options are:

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R)
Assertion (A): In expensive scientific instruments, silica gel is kept in watch-glasses or in semipermeable membrane bags
Reason (R): Silica gel adsorbs moisture from air via adsorption, thus protects the instrument from water corrosion (rusting) and / or prevents malfunctioning
In the light of the above statements, choose the correct answer from the options given below :

Caprolactam when heated at high temperature in presence of water, gives

The normal rain water is slightly acidic and its $pH$ value is $56$ because of which one of the following ?

Amongst the following compounds, which one is an antacid?

Which of the following elements have half-filled f-orbitals in their ground state?
(Given : atomic number $Sm =62 ; Eu =63 ; Tb =65 ; Gd =64, Pm =61$ )
A. $Sm$
B. $Eu$
C. $Tb$
D. $Gd$
E. $Pm$
Choose the correct answer from the options given below :

Lithium aluminium hydride can be prepared from the reaction of

Match List I with List II:

LIST I (Type)	LIST II (Name)
(P) Antifertility drugs	(A) Norethindrone
(Q) Antihistamines	(B) Seldane
(R) Tranquilizers	(C) Meprobamate
(S) Antibiotics	(D) Penicillin

Choose the correct answer from the options given below:

Freezing point of solution is less than that of pure solvent, which of the following statements are correct ?
(A) Vapour pressure of solution is less than that of pure solvent
(B) Vapour pressure of solution is greater than that of pure solvent
(C) Only solvent molecules will freeze
(D) Only solute molecules will freeze

The starting material for convenient preparation of deuterated hydrogen peroxide $\left(D_2 O _2\right)$ in laboratory is :

Find correct order of covalent character (A) $KF < KI$ (B) $CuCl > NaCl$ (C) $LiF > KF$

Number of unpaired electron in highest occupied molecular orbital of following species is :$N_2, N ^+_ 2 , O_2, O^+_ 2 $ ?

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
In the light of the above statements, choose the most appropriate answer from the options given below: