For an isolated system, what will be ?

For the reaction,
   

303.

The heats of combustion of carbon and carbon monoxide are −393.5 and −283.5 kJ mol−1, respectively. The heat of formation (in kJ) of carbon monoxide per mole is:

• 676.5

• -676.5

• -110.5

• -110.5

The following reaction is performed at 298 K
2NO(g) + O₂ (g) ⇌ 2NO₂ (g)
The standard free energy of formation of NO (g) is 86.6 kJ/mol at 298 K. What is the standard free energy of formation of NO₂ (g) at 298 K? (K_P = 1.6 x 10¹²)

• R (298) In (1.6 x 10¹²)-86600

• 86600 + R (298) In (1.6 x 10¹²)

• 86600 - In(1.6 x 10¹²)/R(298)

• 86600 - In(1.6 x 10¹²)/R(298)

The standard Gibbs energy change at 300 K for the reaction, 2A  ⇌ B +C is 2494.2J at a given time, the composition of the reaction mixture is and , The reaction proceeds in the [R= 8.314 JK/mol, e = 2.718]

• forward direction because Q>Kc

• reverse direction because Q>K_c

• forward direction because Q < Kc

• forward direction because Q < Kc

For the complete combustion of ethanol, C₂H₅OH (l) + 3O₂ (g) → 2CO₂ (g) + 3H₂O (l), the amount of heat produced as measured in a bomb calorimeter, is 1364.47 kJ mol-1 at 25^oC. Assuming ideality the enthalpy of combustion, ∆_CH, for the reaction will be (R = 8.314 JK^-1 mol^-1)

• -1366.95 kJ mol^-1

• -1361.95 kJ mol^-1

• -1460.50 kJ mol^-1

• -1460.50 kJ mol^-1

A piston filled with 0.04 mol of an ideal gas expands reversibly from 50.0 mL to 375 mL at a constant temperature of 37.0⁰C. As it does so, it absorbs 208J of heat. The values of q and w for the process will be:(R = 8.314 J/mol K) ( ln 7.5 = 2.01)

• q =+208J, W = - 208 J

• q =-208 J, W =-208 J

• q=-208J, W = +208 J

• q=-208J, W = +208 J

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

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