Thermodynamics ...

Direction (Q. Nos. 1-11) This section contains 11 multiple choice questions. Each question has four choices (a), (b), (c) and (d), out of which ONLY ONE option is correct.

Q. Calorific value of H₂ is - 143 kJ g^-1.Thus, Δ_fH° of H₂O is

In the complete combustion of C₂H₆, 54 g of H₂O is formed and 370 kcal of heat is evolved. Thus, Δ_CH° of C₂H₆ is

The enthalpy of combustion of methane, graphite and dihydrogen at 298 K are - 890.3 kJ mol^-1, - 393.5 kJ mol^-1 and - 285.8 kJ mol^-1 respectively. Enthalpy of formation of CH₄(g) will be

The reaction of cyanamide, NH₂CN (s) was carried out in a bomb calorimeter, and ΔU was found to be - 742.7 kJ mol^-1 at 298 K. Thus, Δ_rH° at 298 K for

Based on the following thermochemical reactions at 298 K and 1 bar

Q. Enthalpy of vaporisation of H₂O (l) is 

For the following combustion reaction of benzoic acid at 298 K

Q. Thus enthalpy of combustion Δ_CH° at 298 K is

The standard enthalpies of formation of CO₂(g), H₂O (l) and glucose (s) at 25°C are - 400 kJ mol^-1, - 300 kJ mol^-1 and - 1300 kJ mol^-1 respectively. The standard enthalpy of combustion per gram of glucose at 25°C is

[JEE Advanced 2013]

For the complete combustion of ethanol,

the amount of heat produced as measured in bomb calorimeter is 1364.47 kJ mol^-1 at 25°C. Assuming ideality, the enthalpy of combustion, Δ_CH° for the reaction Will be (R = 8.314 JK^-1 mol^-1)

[JEE Main 2014]

Given, 

Q. Thus, Δ_fH° of (C₆H₆) (l) is

Δ_fU° of formation of CH₄(g) at a certain temperature is - 393 kJ mol^-1. The value of Δ_fH° is

Heat of combustion of H₂(g) is - 58 kcal mol^-1 at 298 K and constant pressure.

Q. Temperature of a hydrogen-oxygen flame if H₂(g) is used as fuel is