The compound that is most susceptible to a nucleophilic attack in the carbonyl group is:

1. ${\mathrm{CH}}_3{\mathrm{COOCH}}_3$

2. ${\mathrm{CH}}_3{\mathrm{CONH}}_2$

3. ${\mathrm{CH}}_3{\mathrm{COOCOCH}}_3$

4. ${\mathrm{CH}}_3\mathrm{COCl}$

25.3 g of sodium carbonate, Na₂CO₃, is dissolved in enough water to make 250 mL of a solution. If sodium carbonate completely dissociates, the molar concentrations of sodium ion, Na⁺ and carbonate ion, $C{O}_3^{2-}$are respectively:
(molar mass of Na₂CO₃ = 106g mol^-1)

1. 0.955 M and 1.910 M
2. 1.910 M and 0.955 M
3. 1.90 M and 1.910 M
4. 0.477 M and 0.477 M

In a buffer solution containing an equal concentration of B^- and HB, the K_b for B^- is 10^-10. pH of the buffer solution is:

The existence of two different coloured complexes with the composition of [Co(NH₃)₄Cl₂]⁺is due to:

1. Linkage isomerism

2. Geometrical isomerism

3. Coordination isomerism

4. Ionisation isomerism

Among the given options, what is the property of the alkaline earth metals that increases with their atomic number?
1. Solubility of their hydroxides in water
2. Solubility of their sulphates in water
3. Ionization energy
4. Electro-negativity

During the kinetic study of the reaction, 2A + B\( \rightarrow\)C + D, following results were obtained:

Based on the above data which one of the following is correct?

1. rate= k[A]²[B]

2. rate= k[A][B]

3. rate= k[A]²[B]²

4. rate= k[A][B]²

Which of the following pairs has nearly the same ionic size?

The correct order of the decreasing ionic radii among the following isoelectronic species is:

1. $C{a}^{2+}>K^{+}>S^{2-}>C{l}^{-}$

2. $C{l}^{-}>S^{2-}>C{a}^{2+}>K^{+}$

3. $S^{2-}>C{l}^{-}>K^{+}>C{a}^{2+}$

4. $K^{+}>C{a}^{2+}>C{l}^{-}>S^{2-}$

In which one of the following species the central atom has the type of hybridization which is not the same as that present in the other three?

1. ${\mathrm{SF}}_4$

2. ${\mathrm{I}}_3^{-}$

3. ${\mathrm{SbCl}}_5^{2-}$

4. ${\mathrm{PCl}}_5$

Standard entropies of X₂, Y₂ and XY₃ are 60, 40 and 50JK^-1mol^-1 respectively. For the reaction 
$\frac{1}{2}{\mathrm{X}}_2$ $+$ $\frac{3}{2}{\mathrm{Y}}_2$ $$ $\leftrightharpoons$ ${\mathrm{XY}}_3$ $;$ $∆\mathrm{H}$ $=$ $-30$ $\mathrm{kJ}$ to be at equilibrium, the temperature should be:

1. 750 K

2. 1000 K

3. 1250 K

4. 500 K