List of top Chemistry Questions

The pH at which Mg(OH)\(_2\) \([K_{sp} = 1 \times 10^{-11}]\) begins to precipitate from a solution containing 0.10 M Mg\(^{2+}\) ions is \( \_\_\_\_ \).

Choose the correct statements from the following:
A Ethane-1,2-diamine is a chelating ligand.
B Metallic aluminium is produced by electrolysis of aluminium oxide in presence of cryolite.
C Cyanide ion is used as a ligand for leaching of silver.
D Phosphine acts as a ligand in Wilkinson catalyst.
E The stability constants of \( \text{Ca}^{2+} \) and \( \text{Mg}^{2+} \) are similar to EDTA complexes.

The Lassaigne’s extract is boiled with dil HNO\(_3\) before testing for halogens because

Following is a confirmatory test for aromatic primary amines. Identify reagent (A) and (B)

Match List-I with List-II
\[ \begin{array}{|c|c|} \hline \text{List-I (Species)} & \text{List-II (Electronic distribution)} \\ \hline \text{(A) Cr}^{+2} & \text{(I) } 3d^8 \\ \text{(B) Mn}^{+} & \text{(II) } 3d^3 4s^1 \\ \text{(C) Ni}^{+2} & \text{(III) } 3d^4 \\ \text{(D) V}^{+} & \text{(IV) } 3d^5 4s^1 \\ \hline \end{array} \]

What happens to freezing point of benzene when small quantity of napthalene is added to benzene?

Given below are two statement one is labeled as Assertion (A) and the other is labeled as Reason (R).
Assertion (A): CH₂ = CH – CH₂ – Cl is an example of allyl halide
Reason (R): Allyl halides are the compounds in which the halogen atom is attached to sp² hybridised carbon atom.
In the light of the two above statements, choose the most appropriate answer from the options given below

In the given reactions identify the reagent A and reagent B

Structure of 4-Methylpent-2-enal is

Example of vinylic halide is

Given below are the two statements: one is labelled as Assertion (A) and the other is labeled as Reason (R).
Assertion (A): There is a considerable increase in covalent radius from N to P. However from As to Bi only a small increase in covalent radius is observed.
Reason (R): covalent and ionic radii in a particular oxidation state increases down the group.
In the light of the above statement, choose the most appropriate answer from the options given below:

Given below are two statements:
Statement-I: The gas liberated on warming a salt with dil H₂SO₄, turns a piece of paper dipped in lead acetate into black, it is a confirmatory test for sulphide ion.
Statement-II: In statement-I the colour of paper turns black because of formation of lead sulphite. In the light of the above statements, choose the most appropriate answer from the options given below:

Calculate the Molarity of a Solution having density = \(1.5\) \(g/ml\). \(\%(w/w)\) of Solute is \(36\%\) and Molecular weight of Solute is \(36\) \(g/mol\)

How many of the following vitamins are stored in Human Body?
A, B, C, D, E, K?

Match the following : 

(a) \([Cr(H_2O)_6]^{+3}\)	(i) \(t^2_{2g}eg^0\)
(b) \([Fe(H_2O)_6]^{+3}\)	(ii) \(t^3_{2g}eg^0\)
\((c) [Ni(H_2O)_6]^{+2}\)	(iii) \(t^3_{2g}eg^2\)
(d) \([V(H_2O)_6]^{+3}\)	(iv) \(t^6_{2g}eg^2\)

Number of moles of \(H^+\) required by \(1\) mole \(MnO_4^-\) to oxidize oxalate ion to \(CO_2\) is ____ .

What will be the reactivity order of following compounds towards electrophilic substitution reaction ?

Choose the correct answers. 

1. \(Mn_2O_7 \) is a oil at room temperature. 
2. \(V_2O_4\) react with acid to give \(VO^{2+}\).
3. \(CrO\) is a basic oxide.
4. \(V_2O_5\) does not react with acids.

Quantum number for outermost electron of K-atom are given by

Which of the following has maximum ionic character?

Statement-I : Among \(15^{th}\) group hydrides reducing character decreases from
\(NH_3\) to \(BiH_3\).
Statement-II : \(E_2O_3\) and \(E_2O_5\) are always basic. [Where \(E\) is group \(15\) element]

Half life of a first order reaction is \(36\;hr\). Find out time (in hour) required for concentration of reactant to get reduced by \(90\%\).

A compound \((x)\) with molar mass \(108\) \(g\) \(mol^{-1}\) undergoes acetylation to give product with molar mass \(192\) \(g\) \(mol^{-1}\)

Statement I: So disproportionates into \(H_2S_2O_3\) and \(S_2^-\) in alkaline medium 
Statement II: \(ClO_4^-\) undergoes disproportionation in acidic medium

If \(5\) moles of an ideal gas expands from \(10\) L to a volume of \(100\) L at \(300k\) under isothermal and reversible condition then work, \(W\), is \(- x J\). The value of x is \((even \;n = 8.314 \;J \;K^{-1} mol^{-1})\)