List of top Chemistry Questions

According to Bohr's model of hydrogen atom, which of the following statement is incorrect?

The property/properties that show irregularity in the first four elements of group-17 are:

An optically active alkyl halide C$_4$H$_9$Br [A] reacts with hot KOH dissolved in ethanol and forms alkene [B] as major product which reacts with bromine to give dibromide [C]. The compound [C] is converted into a gas [D] upon reacting with alcoholic NaNH$_2$. During hydration 18 gram of water is added to 1 mole of gas [D] on warming with mercuric sulphate and dilute acid at 333 K to form compound [E]. The IUPAC name of compound [E] is :

Identify the structure of the final product (D) in the following sequence of the reactions :

Total number of $ sp^2 $ hybridised carbon atoms in product D is _____.

The number of paramagnetic metal complex species among $ [Co(NH_3)_6]^{3+}, [Co(C_2O_4)_3]^{3-}, [MnCl_6]^{3-}, [Mn(CN)_6]^{3-}, [CoF_6]^{3-}, [Fe(CN)_6]^{3-} $ and $ [FeF_6]^{3-} $ with same number of unpaired electrons is _____.

Butane reacts with oxygen to produce carbon dioxide and water following the equation given below:
$ C_4H_{10}(g) + \frac{13}{2} O_2(g) \rightarrow 4CO_2(g) + 5H_2O(l) $ If 174.0 kg of butane is mixed with 320.0 kg of $ O_2 $, the volume of water formed in litres is _____. (Nearest integer)
[Given: (a) Molar masses: C = 12, H = 1, O = 16 g $ mol^{-1} $; (b) Density of water = 1 g $ mL^{-1} $]

In Dumas' method 292 mg of an organic compound released 50 mL of nitrogen gas ($ N_2 $) at 300 K temperature and 715 mm Hg pressure. The percentage composition of 'N' in the organic compound is _____ % (Nearest integer) (Aqueous tension at 300 K = 15 mm Hg)

Only litre buffer solution was prepared by adding 0.10 mol each of $ NH_3 $ and $ NH_4Cl $ in deionised water. The change in pH on addition of 0.05 mol of HCl to the above solution is _____ $ \times 10^{-2} $, (Nearest integer) (Given : $ pK_b $ of $ NH_3 = 4.745 $ and $ \log_{10}3 = 0.477 $)

The correct statements from the following are :
(A) $ Tl^{3+} $ is a powerful oxidising agent
(B) $ Al^{3+} $ does not get reduced easily
(C) Both $ Al^{3+} $ and $ Tl^{3+} $ are very stable in solution
(D) $ Tl^+ $ is more stable than $ Tl^{3+} $
(E) $ Al^{3+} $ and $ Tl^+ $ are highly stable
Choose the correct answer from the options given below :

The extra stability of half-filled subshell is due to
(A) Symmetrical distribution of electrons
(B) Smaller coulombic repulsion energy
(C) The presence of electrons with the same spin in non-degenerate orbitals
(D) Larger exchange energy
(E) Relatively smaller shielding of electrons by one another
Identify the correct statements

Given below are two statements :

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

The number of optically active products obtained from the complete ozonolysis of the given compound is :

The number of unpaired electrons responsible for the paramagnetic nature of the following complex species are respectively : $ [Fe(CN)_6]^{3-}, [FeF_6]^{3-}, [CoF_6]^{3-}, [Mn(CN)_6]^{3-} $

Match List-I with List-II

Choose the correct answer from the options given below :

'X' is the number of acidic oxides among $ VO_2, V_2O_3, CrO_3, V_2O_5 $ and $ Mn_2O_7 $. The primary valency of cobalt in $ [Co(H_2NCH_2CH_2NH_2)_3]_2 (SO_4)_3 $ is Y. The value of X + Y is :

Match List-I with List-II

Choose the correct answer from the options given below :

Choose the incorrect trend in the atomic radii (r) of the elements :

"P" is an optically active compound with molecular formula $ C_6H_{12}O $. When "P" is treated with 2,4-dinitrophenylhydrazine, it gives a positive test. However, in presence of Tollens reagent, "P" gives a negative test. Predict the structure of "P".

Mixture of 1 g each of chlorobenzene, aniline and benzoic acid is dissolved in 50 mL ethyl acetate and placed in a separating funnel, 5 M NaOH (30 mL) was added in the same funnel. The funnel was shaken vigorously and then kept aside. The ethyl acetate layer in the funnel contains :

Given below are two statements :
Statement (I) : On hydrolysis, oligo peptides give rise to fewer number of $ \alpha $-amino acids while proteins give rise to a large number of $ \beta $-amino acids.
Statement (II) : Natural proteins are denatured by acids which convert the water soluble form of fibrous proteins to their water insoluble form.
In the light of the above statements, choose the most appropriate answer from the options given below :

The total number of structural isomers possible for the substituted benzene derivatives with the molecular formula $C_7H_{12}$ is __

Among, Sc, Mn, Co and Cu, identify the element with highest enthalpy of atomisation. The spin only magnetic moment value of that element in its +2 oxidation state is _______BM (in nearest integer).

X g of nitrobenzene on nitration gave 4.2 g of m-dinitrobenzene. X =_____ g. (nearest integer) [Given : molar mass (in g mol$^{-1}$) C : 12, H : 1, O : 16, N : 14]

What is the correct IUPAC name of

The sequence from the following that would result in giving predominantly 3, 4, 5 -Tribromoaniline is :