The enthalpies of combustion of carbon and carbon monoxide are -393.5 and -283 kJ mol respectively. The enthalpy of formation of carbon monoxide per mole is

• 110.5 kJ

• 676.5 kJ

• -676.5 kJ

• -110.5 kJ

Which one of the following does not have sp² hybridised carbon ?

• Acetone

• Acetic acid

• Acetonitrile

• Acetamide

The temperature dependence of rate constant (k) of a chemical reaction is written in terms of Arrhenius equation, k = Ae^{-E*/ RT}. Activation energy (E*) of the reaction can be calculated by plating

• log k vs $\frac{1}{\mathrm{T}}$

• log k vs $\frac{1}{\log \mathrm{T}}$

• k vs T

• k vs $\frac{1}{\log \mathrm{T}}$

Formation of a solution from two components can be considered as

(1) pure solvent → separated solvent molecules, $∆$H₁

(2) pure solute → separated solute molecules, $∆$H₂

(3) separated solvent and solute molecules → solution, $∆$H₃ 

Solution so formed will be ideal if

• $∆{\mathrm{H}}_{\mathrm{soln}} = ∆{\mathrm{H}}_1 - ∆{\mathrm{H}}_2 - ∆$H₃

• $∆{\mathrm{H}}_{\mathrm{soln}} = ∆{\mathrm{H}}_3 - ∆{\mathrm{H}}_1 - ∆{\mathrm{H}}_2$

• $∆{\mathrm{H}}_{\mathrm{soln}} = ∆{\mathrm{H}}_1 + ∆{\mathrm{H}}_2 + ∆{\mathrm{H}}_3$

• $∆{\mathrm{H}}_{\mathrm{soln}} = ∆{\mathrm{H}}_1 + ∆{\mathrm{H}}_2 - ∆{\mathrm{H}}_3$

15.

Among the following, the pair in which the two species are not isostructural, is

• SiF₄ and SF₄

• IO${}_3^{-}$ and XeO₃

• BH${}_4^{-} \mathrm{and} {\mathrm{NH}}_4^{+}$

• PF${}_6^{-}$ and SF₆

The maximum number of molecule is present in

• 15 L of H₂ gas at STP

• 5 L of N₂ gas at STP

• 0.5 g of H₂ gas

• 10 g of O₂ gas

Ionic radii are

• inversely proportional to effective nuclear charge

• inversely proportional to square of effective nuclear charge

• directly proportional to effective nuclear charge

• directly proportional to square of effective nuclear charge

The helical structure of protein is stabilized by

• dipeptide bond

• hydrogen bonds

• ether bonds

• peptide bonds

The radioactive isotope ${}_{27}{}^{60}\mathrm{Co}$ which is used in the treatment of cancer can be made by (n, p) reaction. For this reaction the target nucleus is

• ${}_{28}{}^{59}\mathrm{Ni}$

• ${}_{27}{}^{59}\mathrm{Co}$

• ${}_{28}{}^{60}\mathrm{Ni}$

• ${}_{27}{}^{60}\mathrm{Co}$

The work done during the expansion of a gas from a volume of 4 dm³ to 6 dm³ against a constant external pressure of 3 atm, is

• -6 J

• -608 J

• +304 J

• -304 J