JEE Main 2019 (Online) 11th January Evening Slot | Thermodynamics Question 176 | Chemistry

The reaction, MgO(s) + C(s) $$ \to $$ Mg(s) + CO(g), for which $$\Delta $$_rH^o + 491.1 kJ mol^{^–1} and $$\Delta $$_rS^o = 198.0 JK^–1 mol^–1, is not feasible at 298 K. Temperature above which reaciton will be feasible is :

2480.3 K

2040.5 K

2380.5 K

1890.0 K

JEE Main 2019 (Online) 11th January Morning Slot

MCQ (Single Correct Answer)

-1

For the chemical reaction X $$\rightleftharpoons$$ Y, the standard reaction Gibbs energy depends on temperature T (in K) as $$\Delta $$_rG^o (in kJ mol^–1) = 120 $$ - {3 \over 8}$$ T.

The major component of the reaction mixture at T is :

Y if T = 300 K

Y if T = 280 K

X if T = 350 K

X if T = 315 K

JEE Main 2019 (Online) 11th January Morning Slot

MCQ (Single Correct Answer)

-1

Two blocks of the same metal having same mass and at temperature T₁ and T₂, respectively, are brought in contact with each other and allowed to attain thermal equilibrium at constant pressure. The change in entropy, $$\Delta $$S, for this process is :

2C_p In $$\left[ {{{{{\left( {{T_1} + {T_2}} \right)}^{{1 \over 2}}}} \over {{T_1}{T_2}}}} \right]$$

2C_p In $$\left[ {{{\left( {{T_1} + {T_2}} \right)} \over {2{T_1}{T_2}}}} \right]$$

C_p In $$\left[ {{{{{\left( {{T_1} + {T_2}} \right)}^2}} \over {4{T_1}{T_2}}}} \right]$$

2C_p In $$\left[ {{{\left( {{T_1} + {T_2}} \right)} \over {4{T_1}{T_2}}}} \right]$$

JEE Main 2019 (Online) 10th January Evening Slot

MCQ (Single Correct Answer)

-1

The process with negative entropy change is :

Dissociation of CaSO₄ (s) to CaO(s) and SO₃(g)

Dissolution of iodine in water

Synthesis of ammonia from N₂ and H₂

Sublimation of dry ice