GATE CY 2019 Question Paper (02-Feb-2019) (Shift 1)

The specific rotation of optically pure (R)-2-bromobutane is -112.00. A given sample of 2-bromobutane exhibited a specific rotation of -82.88. The percentage of (S)-(+)-enantiomer present in this sample is _______.

Consider the following two parallel irreversible first order reactions at temperature T,



where k1 and k2 are the constants and their values are 5 × 10⁻² and 15 × 10⁻² min⁻¹ respectively, at temperature T. If the initial concentration of the reactant 'P' is 4 mol L⁻¹, then the concentration of product 'R' after 10 min of reaction is _______ mol L⁻¹. (Round off to two decimal places)

(Assume only P is present at the beginning of the reaction.)

Consider the following equilibrium

SO2(g) + $\frac{1}{2}$ O2$\leftrightharpoons$ SO3(g)

At 298 K, the standard molar Gibbs energies of formation, ΔrG⁰, of SO2 (g) and SO3 (g) are -300 and -371 kJ mol⁻¹, respectively. The value of the equilibrium constant, KP, at this temperature is _______ × 10¹⁰. (Round off to the nearest integer)

(Gas constant R = 8.31 J mol⁻¹ K⁻¹)

Consider the electrochemical cell

M(s) | MI₂(s) | MI₂(aq) | M(s)

where 'M' is a metal. At 298 K, the standard reduction potentials are

$E_{M^2}^O+(aq)/M(s)=-0.12V$, $E_{M{I}_2(s)/M(s)}^O=-0.36V$ and the temperature coefficient is ${\left(\frac{\partial E_{cell}^0}{\partial T}\right)}_P$ = 1.5 × 10⁻⁴ VK⁻¹. At this temperature the standard enthalpy change for the overall cell reaction, ΔᵣH⁰, is _______ kJ mol⁻¹. (Round off to two decimal places)

(Faraday constant F = 96500 C mol⁻¹)

The normal boiling point of a compound (X) is 350 K (heat of vaporization, Δvap H, = 30 kJ mol⁻¹). The pressure required to boil 'X' at 300 K is _______ Torr. (Round off to two decimal places)

(Ignore the temperature variation of ΔvapH; Gas constant R = 8.31 J mol⁻¹K⁻¹ and 1 atm = 760 Torr)