IIT-JEE 1993

Pick out the isoelectronic structures from the following
I. \(CH_3^+\) II. \(H_3O^+\)
III. \(NH_3\)
IV. \(CH_3^-\)

The dipole moment of KCl is 3.336 \(\times\) 10-29 Coulomb meters which indicates that it is a highly polar molecule. The interatomic distance between K+ and Cl- in this molecule is 2.6 \(\times\) 10-10. Calculate the dipole moment of KCl m...

The dipole moment of CH3F is greater than of CH3Cl

A first order reaction A \(\to\) B, requires activation energy of 70 kJ mol-1. When 20% solution of A was kept at 25oC for 20 minutes, 25% decomposition tooks place. What will be the percentage decomposition in the same time in a 30% soluti...

The standard reduction potential for the half-cell
\(NO_3^-\) + 2H+ (aq) + e \(\to\) NO2 (g) + H2O is 0.78 V
(i) Calculate the reduction potential in 8 M H+
(ii) What will be the reduction potential of the half-cell in a neutral solution? A...

Chromium metal can be plated out from an acidic solution containing CrO3 according to the following equation
CrO3 (aq) + 6H+ (aq) + 6e- \(\to\) Cr(s) + 3H2O
Calculate (i) how many grams of chromium will be plated out by 24,000 coulombs and...

A gas bulb of 1 litre capacity contains 2.0 \(\times\) 1021 molecules of nitrogen exerting a pressure of 7.57 \(\times\) 103 Nm-2. Calculate the root mean square (r.m.s) speed and the temparature of the gas molecules. If the ratio of the m...

In the van der Waal's equation (P + \({{{n^2}a} \over {{V^2}}}\))(V - nb) = nRT the constant 'a' reflects the actual volume of the gas molecules.

Give briefly the isolation of magnesium from sea water by the Dow process. Give equations for the steps involved.

The basic nature of the hydroxides of group 13 (Gr. III B) decreases progressively down the group.

The decreasing order of electron affinity of F, Cl, Br is F > Cl > Br

Ca2+ has a small ionic radius than K+ because it has ______.

What weight of the non-volatile solute, urea(NH2 - CO - NH2) needs to be dissolved in 100g of water, in order to decrease the vapour pressure of water by 25%? What will be the molality of the solution?

Upon mixing 45.0 ml. of 0.25 M lead nitrate solution with 25.0 ml. of 0.10M chromic sulphate solution, precipitation of lead sulphate takes place. How many moles of lead sulphate are formed? Also, calculate the molar concentrations of the s...

In a given electric field, \(\beta-particles\) are deflected more than \(\alpha-particles\) in spite of \(\alpha-particles\) having larger charge.

Wave functions of electrons in atoms and molecules are called ______.

What transition in the hydrogen spectrum would have the same wavelength as the Balmer transition n = 4 to n = 2 of He+ spectrum?

Estimate the difference in energy between 1st and 2nd Bohr orbit for a hydrogen atom. At what minimum atomic number, a transition from n = 2 to n = 1 energy level would result in the emission of X-rays with $$\lambda = 3.0 \times {10^{ - 8...

The 2px, 2py and 2pz orbitals of atom have identical shapes but differ in their _____.

The light radiations with discrete quantities of energy are called ______.