List of top Chemistry Questions

Which one is a wrong statement ?

Consider the following species :
CN⁺, CN^–, NO and CN
Which one of these will have the highest bond order ?

The correction factor ‘a’ to the ideal gas equation corresponds to

Hydrocarbon (A) reacts with bromine by substitution to form an alkyl bromide which by Wurtz reaction is converted to gaseous hydrocarbon containing less than four carbon atoms. (A) is

Iron exhibits bcc structure at room temperature. Above 900°C, it transforms to fcc structure. The ratio of density of iron at room temperature to that at 900°C (assuming molar mass and atomic radii of iron remains constant with temperature) is

Magnesium reacts with an element (X) to form an ionic compound. If the ground state electronic configuration of (X) is 1s² 2s² 2p³ , the simplest formula for this compound is

In which case is the number of molecules of water maximum ?

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

Among CaH₂ , BeH₂ , BaH₂ , the order of ionic character is

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

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

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

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

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

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

In the reaction

the electrophile involved is