The cyanide ion, CN^- and N₂ are isoelectronic, But in contrast to CN^-, N₂ is chemically inert, because of

For the redox reaction:
$$MnO_4^ - + {C_2}O_4^{ - 2} + {H^ + }$$ $$ \to M{n^{2 + }} + C{O_2} + {H_2}O$$
The correct coefficients of the reactants for the balanced reaction are

A 2.0 g sample of a mixture containing sodium carbonate, sodium bicarbonate and sodium suplphate is gently heated till the evolution of CO₂ ceases. The volume of CO₂ at 750 mm Hg pressure and at 298K is measured to be 123.9 ml. A 1.5g of the same sample requires 150 ml. of (M/10) HCl for complete neutralisation. Calculate the % composition of the components of the mixture.

One gram of commercial AgNO₃ is dissolved in 50 ml. of water. It is treated with 50 ml. of a KI solution. The silver iodide thus precipitated is filtered off. Excess of KI in the filterate is titrated with (M/10) KIO₃ solution in presence of 6M HCl till all I^- ions are converted into ICl. It requires 50 ml. of (M/10) KIO₃ solution. 20 ml. of the same stock solution of KI requires 30 ml. of (M/10) KIO₃ under similar conditions. Calculate the percentage of AgNO₃ in the sample.
(Reaction : KIO₃ + 2KI + 6HCl $$\to$$ 3ICl + 3KCl + 3H₂O)

Which of the following relates to photons both as wave motion and as a stream of particles?

Which of the following does not characterise X-rays?

The statement that is not correct for the periodic classification of element is

The maximum number of hydrogen bonds a water molecule can form is

The type of hybrid orbitals used by the chlorine atom in $$ClO_2^-$$ is

Which of the following have identical bond order?

The molecules that will have dipole moment are

At 27^oC, hydrogen is leaked through a tiny hole into a vessel for 20 minutes. Another unknown gas at the same temperature and pressure as that of H₂ is leaked through the same hole for 20 minutes After the effusion of the gases the mixture exerts a pressure of 6 atmosphere. The hydrogen content of the mixture is 0.7 mole. If the volume of ther container is 3 litres, what is the molecular weight of the unknown gas?

At room temperature the following reacton is procedd nearly to completion:

2NO + O₂ $$\to$$ 2NO₂ $$\to$$ N₂O₄

The dimer, N₂O₄, solidifies at 262 K. A 250 ml flask and a 100 ml flask are separated by a stop-cock. At 300 K, the nitric oxide in the larger flask exerts a pressure of 1.053 atm. and the smaller one contains oxygen at 0.789 atm. The gases are mixed by the opening stopcock and after the end of raction the flasks are cooled at 220K. Neglecting the vapour pressure of the dimer, find out the pressure and composition of the gas remaining at 220 K. (Assume the gases to behave ideally)

The species that do not contain peroxide ions are

Give reasons of the following:
Hydrogen peroxide acts as an oxidising as well as a reducing agent.

For the galvanic cell
Ag | AgCl(s), KCl (0.2M) || KBr (0.001M), AgBr(s) | Ag
Calculate the EMF generated and assign correct polarity to each electrode for a spontaneous process after taking into account the cell reaction at 25^oC.
[K_sp(AgCl) = 2.8 $$times$$ 10^-10; K_sp(AgBr) = 3.3 $$times$$ 10^-13]

An aqueous solution of NaCl on electrolysis gives H₂(g), Cl₂(g) and NaOH according to the reaction:
2Cl^- (aq) + 2H₂O = 2OH^- (aq) + H₂ (g) + Cl₂ (g)
A direct current of 25 amperes with a current efficiency of 62 % is passed through 20 litres of NaCl solution (20% by weight). Write down the reactions taking place at the anode and cathode. How long will it take to produce 1kg of Cl₂? What will be the molarity of the solution with respect to hydroxide ion? (Assume no loss due to evaporation)