Which of the following molecules has trigonal planar geometry?

• IF₃

• PCl₃

• NH₃

• BF₃

The correct sequence of increasing covalent character is represented by

• LiCl < NaCl < BeCl₂

• BeCl₂ < NaCl < LiCl

• NaCl < LiCl < BeCl₂

• BeCl₂ < LiCl < NaCl

The mass of carbon anode consumed (giving only carbondioxide) in the production of 270 kg of aluminium metal from bauxite by the Hall process is (Atomic mass Al= 27)

• 180 kg

• 270 kg

• 540 kg

• 90 kg

Which of the following is the electron deficient molecule?

• B₂H₆

• C₂H₆

• PH₃

• SiH₄

A reaction occurs spontaneously if

• T$∆$S < $∆$H and both $∆$H and $∆$S are +ve

• T$∆$S > $∆$H and both $∆$H and $∆$S are +ve

• T$∆$S = $∆$H and both $∆$H and $∆$S are +ve

• T$∆$S > $∆$H and $∆$H is +ve and $∆$S is - ve

The absolute enthalpy of neutralisation of the reaction

MgO(s) + 2HCl(aq) $\to$ MgCl₂(aq) + H₂O(l)

will be

• less than - 57.33 kJ mol^-1

• - 57.33 kJ mol^-1

• greater than-- 57.33 kJ mol^-1

• 57.33 kJ mol^-1

The number of moles of KMnO₄ reduced by one mole of KI in alkaline medium is

• one-fifth

• five

• one

• two

A nuclide of an alkaline earth metal undergoes radioactive decay by emission of three $\mathrm{\alpha }$-particles in succession. The group of the periodic table to which the resulting daughter element would belong to

• Group 14

• Group 16

• Group 4

• Group 6

9.

Which of the following pairs of a chemical reaction is certain to result in a spontaneous reaction?

• Exothermic and decreasing disorder

• Endothermic and increasing disorder

• Exothermic and increasing disorder

• Endothermic and decreasing disorder

Equilibrium constants K₁ and K₂ for the following equilibria
NO (g) + $\frac{1}{2}{\mathrm{O}}_2$ $\stackrel{{\mathrm{K}}_1}{\rightleftharpoons }$ NO₂(g) and

2NO₂(g) $\stackrel{{\mathrm{K}}_2}{\rightleftharpoons }$ 2NO (g) + O₂(g)

are related as

• ${\mathrm{K}}_2 = \frac{1 }{{\mathrm{K}}_1}$

• ${\mathrm{K}}_2 = {\mathrm{K}}_1^2$

• ${\mathrm{K}}_2 = \frac{{\mathrm{K}}_1}{2}$

• ${\mathrm{K}}_2 =\frac{1}{{\mathrm{K}}_1^2}$