List of top Chemistry Questions

The bond dissociation energies of X₂ , Y₂ and XY are in the ratio of 1 : 0·5 : 1. ΔH for the formation of XY is – 200 kJ mol^–1 . The bond dissociation energy of X₂ will be

When initial concentration of the reactant is doubled, the half-life period of a zero order reaction

For the redox reaction
\(MnO_4^-+C_2O^{2-}_4+H^+→Mn^{2+}+CO_2+H_2O\)
the correct coefficients of the reactants for the balanced equation are

Which one of the following conditions will favour maximum formation of the product in the reaction,
A₂(g) + B₂(g) ⇌ X₂(g) Δ_rH = – X kJ ?

Consider the change in oxidation state of Bromine corresponding to different emf values as shown in the diagram below :

Then the species undergoing disproportionation is

The correct difference between first- and second-order reactions is that

Iron carbonyl, Fe(CO)₅ is

Which one of the following ions exhibits d-d transition and paramagnetism as well ?

Match the metal ions given in Column I with the spin magnetic moments of the ions given in Column II and assign the correct code :

Column I		Column II
a.	Co3+	i.	\(\sqrt8\) B.M.
b.	Cr3+	ii.	\(\sqrt{35}\) B.M.
c.	Fe3+	iii.	\(\sqrt3\) B.M.
d.	Ni2+	iv.	\(\sqrt{24}\) B.M.
		v.	\(\sqrt{15}\) B.M.

The geometry and magnetic behaviour of the complex [Ni(CO)₄] are

Which of the following carbocations is expected to be most stable ?

The type of isomerism shown by the complex [CoCl₂(en)₂] is

Which of the following is correct with respect to – I effect of the substituents ? (R = alkyl)

Carboxylic acids have higher boiling points than aldehydes, ketones and even alcohols of comparable molecular mass. It is due to their

A mixture of 2.3 g formic acid and 4.5 g oxalic acid is treated with conc. H₂SO₄ . The evolved gaseous mixture is passed through KOH pellets. Weight (in g) of the remaining product at STP will be

The difference between amylose and amylopectin is

Compound A, C₈H₁₀O, is found to react with NaOI (produced by reacting Y with NaOH) and yields a yellow precipitate with characteristic smell.
A and Y are respectively

In the reaction

the electrophile involved is

Which one of the following elements is unable to form MF₆^3-ion ?

Nitration of aniline in strong acidic medium also gives m-nitroaniline because

The correct order of N-compounds in its decreasing order of oxidation states is

Which of the following statements is not true for halogens ?

Which of the following oxides is most acidic in nature ?

Regarding cross-linked or network polymers, which of the following statements is incorrect ?

The correct order of atomic radii in group 13 elements is