The entropy change involved in the isothermal reversible expansion of 2 moles of an ideal gas from a volume of 10 dm3 to a volume of 100 dm³ at 27°C is

• 38.3 J mol^-1 K^-1

• 35.8 J  mol^-1 K^-1

• 32.3 J  mol^-1 K^-1

• 32.3 J  mol^-1 K^-1

The standard enthalpy of formation of NH₃ is– 46.0 kJmol^–1. If the enthalpy of formation of H₂ from its atoms is – 436 kJ mol^–1 and that of N₂ is – 712 kJ mol^–1,the average bond enthalpy of N – H bond is NH₃ is

• -964 kJ mol^-1

• +352 kJ mol^-1

• +1056 kJ mol^-1

• +1056 kJ mol^-1

The energy required to break one mole of Cl— Cl bonds in Cl2 is 242 kJ mol^–. The longest wavelength of light capable of breaking a single Cl — Cl bond is
(c= 3 x 10⁸ ms^–1and N_A = 6.02 x 10²³ mol^–1)

• 594 nm

• 640 nm

• 700 nm

• 700 nm

The incorrect expression among the following is

• 

• In isothermal process
  
  

• 
• 

The standard reduction potentials for Zn²⁺/ Zn, Ni²⁺/ Ni, and F²⁺/ Fe are –0.76, –0.23 and –0.44 V respectively. The reaction X + Y²⁺ → X ²⁺ + Y will be spontaneous when

• X = Ni, Y = Fe

• X = Ni, Y = Zn

• X =Fe, Y= Zn

• X =Fe, Y= Zn