Entropy Quiz

What does it mean if a reaction is described as spontaneous?

• It requires an external catalyst to occur.

• It will not occur without continuous energy input.

• It will take place of its own accord.

• It only occurs under specific laboratory conditions.

Does a spontaneous reaction take into account the rate of reaction?

• Yes, it is dependent on the rate of reaction.

• No, it does not take account of rate of reaction.

• Yes, but only in non-equilibrium conditions.

• No, it only depends on temperature.

What is entropy?

• A measure of the dispersal of energy in a system which is greater when the system is more ordered

• A measure of the dispersal of energy in a system which is greater when the system is more disordered

• A measure of the concentration of energy in a system which is greater when the system is more ordered

• A measure of the concentration of energy in a system which is greater when the system is more disordered

What is the unit of standard entropy?

• Joules per Kelvin (J/K)

• Joules per mole (J/mol)

• Joules (J)

• Kelvin (K)

What is the unit of standard entropy?

• J K^-1 mol^-1

• J mol^-1

• K mol^-1

• J K mol

What is the standard enthalpy change of formation (ΔH°f) for ethene (C2H4) according to the thermodynamic data provided?

• 0 kJ mol^-1

• 52 kJ mol^-1

• 131 kJ mol^-1

• 219 kJ mol^-1

What is the standard entropy (S°) of hydrogen gas (H2) according to the thermodynamic data provided?

• 0 J K^-1 mol^-1

• 6 J K^-1 mol^-1

• 131 J K^-1 mol^-1

• 219 J K^-1 mol^-1

What is the free energy change for the reaction at 330 K?

• +18202 kJ mol^-1

• +33.83 kJ mol^-1

• +70.15 kJ mol^-1

• -18098 kJ mol^-1

What is the free energy change for the reaction of ethene production at 330 K?

• A. +18202 kJ mol^-1

• B. +33.83 kJ mol^-1

• C. -70.15 kJ mol^-1

• D. -1089.8 kJ mol^-1

Why is the correct answer for the calculation of ΔG C and not A?

• Because ΔH was not calculated correctly.

• Because TΔS was not subtracted from ΔH.

• Because the units for ΔS were not converted from J K^-1 mol^-1 to kJ K^-1 mol^-1.

• Because the value for ΔS was incorrect.